Dataset Information

Conventions: CF-1.6, ACDD-1.3, ISO-8601
standard_name_vocabulary: CF Standard Name Table v30
project: CYGNSS
featureType: trajectory
summary: CYGNSS is a NASA Earth Venture mission, managed by the Earth System Science Pathfinder Program. The mission consists of a constellation of eight small satellites. The eight observatories comprise a constellation that measures the ocean surface wind field with very high temporal resolution and spatial coverage, under all precipitating conditions, and over the full dynamic range of wind speeds experienced in a tropical cyclone. The CYGNSS observatories fly in 510 km circular orbits at a common inclination of 35°. Each observatory includes a Delay Doppler Mapping Instrument (DDMI) consisting of a modified GPS receiver capable of measuring surface scattering, a low gain zenith antenna for measurement of the direct GPS signal, and two high gain nadir antennas for measurement of the weaker scattered signal. Each DDMI is capable of measuring 4 simultaneous bi-static reflections, resulting in a total of 32 wind measurements per second by the full constellation.
program: CYGNSS
references: Ruf, C., P. Chang, M.P. Clarizia, S. Gleason, Z. Jelenak, J. Murray, M. Morris, S. Musko, D. Posselt, D. Provost, D. Starkenburg, V. Zavorotny, CYGNSS Handbook, Ann Arbor, MI, Michigan Pub., ISBN 978-1-60785-380-0, 154 pp, 1 Apr 2016. http://clasp-research.engin.umich.edu/missions/cygnss/reference/cygnss-mission/CYGNSS_Handbook_April2016.pdf
processing_level: 1
comment: DDMs are calibrated into Power (Watts) and Bistatic Radar Cross Section (m^2)
creator_type: institution
institution: University of Michigan Space Physics Research Lab (SPRL)
creator_name: CYGNSS Science Operations Center
publisher_name: PO.DAAC
publisher_email: podaac@podaac.jpl.nasa.gov
publisher_url: ​http://podaac.jpl.nasa.gov
sensor: Delay Doppler Mapping Instrument (DDMI)
source: Delay Doppler maps (DDM) obtained from the DDMI aboard CYGNSS observatory constellation
version_id: 3.1
title: CYGNSS Level 1 Science Data Record Version 3.1
ShortName: CYGNSS_L1_V3.1
id: PODAAC-CYGNS-L1X31
netcdf_version_id: 4.3.3.1 of Dec 10 2015 16:44:18 $
history: Fri May 27 21:29:16 2022: ncks -O -a -dsample,0,164111,1 -L1 --cnk_dmn=sample,1000 --cnk_dmn=ddm,4 --cnk_dmn=delay,17 --cnk_dmn=doppler,11 /tmp/qt_temp.b27996 /tmp/qt_temp.f27996 ../../src/produce-L1-files/produce-L1-files production_1@cygnss-data-1.engin.umich.edu 3 2022-05-26 00:00:00 2022-05-27 00:00:00 --allow-partial
platform: Observatory Reference: cyg3 (C-SCID=2B)
l1_algorithm_version: 3.1
l1_data_version: 3.2
lna_data_version: 2
nadir_ant_data_version: 17
nadir_sidelobe_mask_version: -1
zenith_ant_data_version: 13
ant_temp_version: 1
eff_scatter_2d_version: 4
eff_scatter_3d_version: 6
nbrcs_scatt_1d_version: 9
gps_eirp_param_version: 7
prn_sv_maps_version: 1
land_mask_version: 1
near_land_mask_version: 1
very_near_land_mask_version: 1
open_ocean_mask_version: 1
ddm_a2d_version: 1
milky_way_version: 1
fresnel_coeff_version: 1
brcs_uncert_lut_version: 3
ddma_les_sel_luts_version: 2
mean_sea_surface_version: 1
zenith_specular_ratio_gain_version: 19
zenith_calibration_params_version: 17
anomalous_sampling_periods_version: 1
noise_floor_correction_version: 9
zenith_sig_i2_q2_correction_version: 4
ddm_nbrcs_scale_factor_version: 6
eirp_scale_factor_version: 2
bin_ratio_qc_version: 1
per_bin_ant_version: 1
date_created: 2022-05-27T21:29:16Z
date_issued: 2022-05-27T21:29:16Z
geospatial_lat_min: -42.045N
geospatial_lat_max: 42.165N
geospatial_lon_min: 0.000E
geospatial_lon_max: 360.000E
time_coverage_resolution: P0DT0H0M1S
time_coverage_start: 2022-05-26T00:00:00.499261785Z
time_coverage_end: 2022-05-26T23:59:59.999261635Z
time_coverage_duration: P1DT0H0M0S
NCO: 4.4.4


Variables in this Dataset

sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
spacecraft_id: 16 bit Integer
long_name: CCSDS spacecraft identifier
units: 1
comment: The CCSDS spacecraft identifier: 0xF7 (247): CYGNSS 1 0xF9 (249): CYGNSS 2 0x2B ( 43): CYGNSS 3 0x2C ( 44): CYGNSS 4 0x2F ( 47): CYGNSS 5 0x36 ( 54): CYGNSS 6 0x37 ( 55): CYGNSS 7 0x49 ( 73): CYGNSS 8 0x00 ( 0): end to end simulator 0x0E ( 14): engineering model 0x0D ( 15): default 0xFF (255): unknown
spacecraft_num: 16 bit Integer
long_name: CYGNSS spacecraft number
units: 1
valid_min: 1
valid_max: 99
comment: The CYGNSS spacecraft number: Ranges from 1 through 8 and 99. 1 through 8 are on-orbit spacecraft. 99 is the CYGNSS end-to-end simulator
ddm_source: 16 bit Integer
long_name: Level 0 data source
valid_range: 0, 3
flag_values: 0, 1, 2, 3
flag_meanings: e2es gpss ddmi unknown
comment: The source of the Level 0 DDM raw counts and metadata. 0 = End-End Simulator (E2ES) 1 = GPS signal simulator 2 = CYGNSS spacecraft 3 = Source unknown
ddm_time_type_selector: 16 bit Integer
long_name: DDM sample time type selector
valid_range: 0, 3
flag_values: 0, 1, 2, 3
flag_meanings: start middle end pvt
comment: Determines the position of ddm_timestamp_utc relative to the DDM sampling period. Set to for nominal science operations. Other settings are used for pre-launch testing only. 0 = Start of DDM sampling period (used for pre-launch testing only) 1 = Middle of DDM sampling period 2 = End of DDM sampling period (used for testing pre-launch only) 3 = pvt_timestamp_utc (used for testing pre-launch only)
delay_resolution: 32 bit Real
long_name: DDM delay bin resolution
units: 1
comment: DDM delay bin resolution in chips. One chip is equal to 1/1,023,000 seconds.
dopp_resolution: 32 bit Real
long_name: DDM Doppler bin resolution
units: s-1
comment: DDM Doppler bin resolution in Hz
ddm_timestamp_utc: Grid
long_name: DDM sample timestamp - UTC
standard_name: time
calendar: gregorian
comment: DDM sample time. The number of seconds since time_coverage_start with nanosecond resolution. Its position relative to the DDM sampling period is determined by ddm_time_type_selector. Some metadata required for DDM calibration are generated relative to pvt_timestamp_utc or att_timestamp_utc. These metadata are interpolated to ddm_timestamp_utc before being used for DDM calibration. Note that the DDM sampling period is not synchronized with the UTC change of second and can occur at any time relative to the UTC change of second.
units: seconds since 2022-05-26 00:00:00.499261785
ddm_timestamp_utc: Array of 64 bit Reals [sample = 0..164111]
long_name: DDM sample timestamp - UTC
standard_name: time
calendar: gregorian
comment: DDM sample time. The number of seconds since time_coverage_start with nanosecond resolution. Its position relative to the DDM sampling period is determined by ddm_time_type_selector. Some metadata required for DDM calibration are generated relative to pvt_timestamp_utc or att_timestamp_utc. These metadata are interpolated to ddm_timestamp_utc before being used for DDM calibration. Note that the DDM sampling period is not synchronized with the UTC change of second and can occur at any time relative to the UTC change of second.
units: seconds since 2022-05-26 00:00:00.499261785
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm_timestamp_gps_week: Grid
long_name: DDM sample timestamp - GPS Week
units: week
comment: The GPS week number of ddm_timestamp_utc
ddm_timestamp_gps_week: Array of 32 bit Integers [sample = 0..164111]
long_name: DDM sample timestamp - GPS Week
units: week
comment: The GPS week number of ddm_timestamp_utc
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm_timestamp_gps_sec: Grid
long_name: DDM sample timestamp - GPS Seconds
units: second
comment: The GPS second of week of ddm_timestamp_utc, with nanosecond resolution
ddm_timestamp_gps_sec: Array of 64 bit Reals [sample = 0..164111]
long_name: DDM sample timestamp - GPS Seconds
units: second
comment: The GPS second of week of ddm_timestamp_utc, with nanosecond resolution
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
pvt_timestamp_utc: Grid
long_name: PVT timestamp - UTC
standard_name: time
calendar: gregorian
comment: The spacecraft position and velocity epoch. The number of seconds since time_coverage_start with nanosecond resolution. This is the timestamp of the position and velocity reported by the DDMI. This is also the timestamp of the most recent GPS pulse per second.
units: seconds since 2022-05-26 00:00:00.499261785
pvt_timestamp_utc: Array of 64 bit Reals [sample = 0..164111]
long_name: PVT timestamp - UTC
standard_name: time
calendar: gregorian
comment: The spacecraft position and velocity epoch. The number of seconds since time_coverage_start with nanosecond resolution. This is the timestamp of the position and velocity reported by the DDMI. This is also the timestamp of the most recent GPS pulse per second.
units: seconds since 2022-05-26 00:00:00.499261785
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
pvt_timestamp_gps_week: Grid
long_name: PVT timestamp - GPS Week
units: week
comment: The GPS week number of pvt_timestamp_utc
pvt_timestamp_gps_week: Array of 32 bit Integers [sample = 0..164111]
long_name: PVT timestamp - GPS Week
units: week
comment: The GPS week number of pvt_timestamp_utc
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
pvt_timestamp_gps_sec: Grid
long_name: PVT timestamp - GPS Seconds
units: second
comment: The GPS second of week of pvt_timestamp_utc, with nanosecond resolution.
pvt_timestamp_gps_sec: Array of 64 bit Reals [sample = 0..164111]
long_name: PVT timestamp - GPS Seconds
units: second
comment: The GPS second of week of pvt_timestamp_utc, with nanosecond resolution.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
att_timestamp_utc: Grid
long_name: Attitude timestamp - UTC
standard_name: time
calendar: gregorian
comment: The spacecraft attitude epoch. The number of seconds since time_coverage_start with nanosecond resolution. This is the timestamp of the spacecraft attitude reported by the spacecraft attitude determinination system.
units: seconds since 2022-05-26 00:00:00.499261785
att_timestamp_utc: Array of 64 bit Reals [sample = 0..164111]
long_name: Attitude timestamp - UTC
standard_name: time
calendar: gregorian
comment: The spacecraft attitude epoch. The number of seconds since time_coverage_start with nanosecond resolution. This is the timestamp of the spacecraft attitude reported by the spacecraft attitude determinination system.
units: seconds since 2022-05-26 00:00:00.499261785
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
att_timestamp_gps_week: Grid
long_name: Attitude timestamp - GPS Week
units: week
comment: The GPS week number of att_timestamp_utc
att_timestamp_gps_week: Array of 32 bit Integers [sample = 0..164111]
long_name: Attitude timestamp - GPS Week
units: week
comment: The GPS week number of att_timestamp_utc
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
att_timestamp_gps_sec: Grid
long_name: Attitude timestamp - GPS Seconds
units: second
comment: The GPS second of week of att_timestamp_utc, with nanosecond resolution
att_timestamp_gps_sec: Array of 64 bit Reals [sample = 0..164111]
long_name: Attitude timestamp - GPS Seconds
units: second
comment: The GPS second of week of att_timestamp_utc, with nanosecond resolution
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
sc_pos_x: Grid
long_name: Spacecraft position X at DDM sample time
units: meter
_FillValue: -99999999
comment: The X component of the spacecraft WGS84 reference frame Earth-Centered Earth-Fixed (ECEF) position, in meters, at ddm_timestamp_utc
sc_pos_x: Array of 32 bit Integers [sample = 0..164111]
long_name: Spacecraft position X at DDM sample time
units: meter
_FillValue: -99999999
comment: The X component of the spacecraft WGS84 reference frame Earth-Centered Earth-Fixed (ECEF) position, in meters, at ddm_timestamp_utc
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
sc_pos_y: Grid
long_name: Spacecraft position Y at DDM sample time
units: meter
_FillValue: -99999999
comment: The Y component of the spacecraft WGS84 reference frame ECEF position, in meters, at ddm_timestamp_utc
sc_pos_y: Array of 32 bit Integers [sample = 0..164111]
long_name: Spacecraft position Y at DDM sample time
units: meter
_FillValue: -99999999
comment: The Y component of the spacecraft WGS84 reference frame ECEF position, in meters, at ddm_timestamp_utc
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
sc_pos_z: Grid
long_name: Spacecraft position Z at DDM sample time
units: meter
_FillValue: -99999999
comment: The Z component of the spacecraft WGS84 reference frame ECEF position, in meters, at ddm_timestamp_utc
sc_pos_z: Array of 32 bit Integers [sample = 0..164111]
long_name: Spacecraft position Z at DDM sample time
units: meter
_FillValue: -99999999
comment: The Z component of the spacecraft WGS84 reference frame ECEF position, in meters, at ddm_timestamp_utc
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
sc_vel_x: Grid
long_name: Spacecraft velocity X at DDM sample time
units: meter s-1
_FillValue: -9999
comment: The X component of the spacecraft WGS84 reference frame ECEF velocity, in m/s, at ddm_timestamp_utc
sc_vel_x: Array of 32 bit Integers [sample = 0..164111]
long_name: Spacecraft velocity X at DDM sample time
units: meter s-1
_FillValue: -9999
comment: The X component of the spacecraft WGS84 reference frame ECEF velocity, in m/s, at ddm_timestamp_utc
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
sc_vel_y: Grid
long_name: Spacecraft velocity Y at DDM sample time
units: meter s-1
_FillValue: -9999
comment: The Y component of the spacecraft WGS84 reference frame ECEF velocity, in m/s, at ddm_timestamp_utc
sc_vel_y: Array of 32 bit Integers [sample = 0..164111]
long_name: Spacecraft velocity Y at DDM sample time
units: meter s-1
_FillValue: -9999
comment: The Y component of the spacecraft WGS84 reference frame ECEF velocity, in m/s, at ddm_timestamp_utc
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
sc_vel_z: Grid
long_name: Spacecraft velocity Z at DDM sample time
units: meter s-1
_FillValue: -9999
comment: The Z component of the spacecraft WGS84 reference frame ECEF velocity, in m/s, at ddm_timestamp_utc
sc_vel_z: Array of 32 bit Integers [sample = 0..164111]
long_name: Spacecraft velocity Z at DDM sample time
units: meter s-1
_FillValue: -9999
comment: The Z component of the spacecraft WGS84 reference frame ECEF velocity, in m/s, at ddm_timestamp_utc
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
sc_pos_x_pvt: Grid
long_name: Spacecraft position X at PVT time
units: meter
_FillValue: -99999999
comment: The X component of the spacecraft WGS84 reference frame ECEF position, in meters, at pvt_timestamp_utc
sc_pos_x_pvt: Array of 32 bit Integers [sample = 0..164111]
long_name: Spacecraft position X at PVT time
units: meter
_FillValue: -99999999
comment: The X component of the spacecraft WGS84 reference frame ECEF position, in meters, at pvt_timestamp_utc
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
sc_pos_y_pvt: Grid
long_name: Spacecraft position Y at PVT time
units: meter
_FillValue: -99999999
comment: The Y component of the spacecraft WGS84 reference frame ECEF position, in meters, at pvt_timestamp_utc
sc_pos_y_pvt: Array of 32 bit Integers [sample = 0..164111]
long_name: Spacecraft position Y at PVT time
units: meter
_FillValue: -99999999
comment: The Y component of the spacecraft WGS84 reference frame ECEF position, in meters, at pvt_timestamp_utc
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
sc_pos_z_pvt: Grid
long_name: Spacecraft position Z at PVT time
units: meter
_FillValue: -99999999
comment: The Z component of the spacecraft WGS84 reference frame ECEF position, in meters, at pvt_timestamp_utc
sc_pos_z_pvt: Array of 32 bit Integers [sample = 0..164111]
long_name: Spacecraft position Z at PVT time
units: meter
_FillValue: -99999999
comment: The Z component of the spacecraft WGS84 reference frame ECEF position, in meters, at pvt_timestamp_utc
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
sc_vel_x_pvt: Grid
long_name: Spacecraft velocity X at PVT time
units: meter s-1
_FillValue: -9999
comment: The X component of the spacecraft WGS84 reference frame ECEF velocity, in m/s, at pvt_timestamp_utc
sc_vel_x_pvt: Array of 32 bit Integers [sample = 0..164111]
long_name: Spacecraft velocity X at PVT time
units: meter s-1
_FillValue: -9999
comment: The X component of the spacecraft WGS84 reference frame ECEF velocity, in m/s, at pvt_timestamp_utc
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
sc_vel_y_pvt: Grid
long_name: Spacecraft velocity Y at PVT time
units: meter s-1
_FillValue: -9999
comment: The Y component of the spacecraft WGS84 reference frame ECEF velocity, in m/s, at pvt_timestamp_utc
sc_vel_y_pvt: Array of 32 bit Integers [sample = 0..164111]
long_name: Spacecraft velocity Y at PVT time
units: meter s-1
_FillValue: -9999
comment: The Y component of the spacecraft WGS84 reference frame ECEF velocity, in m/s, at pvt_timestamp_utc
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
sc_vel_z_pvt: Grid
long_name: Spacecraft velocity Z at PVT time
units: meter s-1
_FillValue: -9999
comment: The Z component of the spacecraft WGS84 reference frame ECEF velocity, in m/s, at pvt_timestamp_utc
sc_vel_z_pvt: Array of 32 bit Integers [sample = 0..164111]
long_name: Spacecraft velocity Z at PVT time
units: meter s-1
_FillValue: -9999
comment: The Z component of the spacecraft WGS84 reference frame ECEF velocity, in m/s, at pvt_timestamp_utc
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
nst_att_status: Grid
long_name: NST attitude status
_FillValue: -99
valid_range: 0, 22
flag_values: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22
flag_meanings: ok not_used2 bad too_few_stars quest_failed residuals_too_high too_close_to_edge pix_amp_too_low pix_amp_too_high backgnd_too_high track_failure pix_sum_too_low unused too_dim_for_starid too_many_groups too_few_groups channel_disabled track_blk_overlap ok_for_starid too_close_to_other too_many_pixels too_many_columns too_many_rows
comment: Nano Star Tracker attitude status as reported by the ADCS subsystem. Enumeration, with 0 indicating OK, and non-zero indicating an erroneous condition. Values: 0 = ok 1 = not_used2 2 = bad 3 = too_few_stars 4 = quest_failed 5 = residuals_too_high 6 = too_close_to_edge 7 = pix_amp_too_low 8 = pix_amp_too_high 9 = backgnd_too_high 10 = track_failure 11 = pix_sum_too_low 12 = unused 13 = too_dim_for_starid 14 = too_many_groups 15 = too_few_groups 16 = channel_disabled 17 = track_blk_overlap 18 = ok_for_starid 19 = too_close_to_other 20 = too_many_pixels 21 = too_many_columns 22 = too_many_rows
nst_att_status: Array of 16 bit Integers [sample = 0..164111]
long_name: NST attitude status
_FillValue: -99
valid_range: 0, 22
flag_values: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22
flag_meanings: ok not_used2 bad too_few_stars quest_failed residuals_too_high too_close_to_edge pix_amp_too_low pix_amp_too_high backgnd_too_high track_failure pix_sum_too_low unused too_dim_for_starid too_many_groups too_few_groups channel_disabled track_blk_overlap ok_for_starid too_close_to_other too_many_pixels too_many_columns too_many_rows
comment: Nano Star Tracker attitude status as reported by the ADCS subsystem. Enumeration, with 0 indicating OK, and non-zero indicating an erroneous condition. Values: 0 = ok 1 = not_used2 2 = bad 3 = too_few_stars 4 = quest_failed 5 = residuals_too_high 6 = too_close_to_edge 7 = pix_amp_too_low 8 = pix_amp_too_high 9 = backgnd_too_high 10 = track_failure 11 = pix_sum_too_low 12 = unused 13 = too_dim_for_starid 14 = too_many_groups 15 = too_few_groups 16 = channel_disabled 17 = track_blk_overlap 18 = ok_for_starid 19 = too_close_to_other 20 = too_many_pixels 21 = too_many_columns 22 = too_many_rows
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
sc_roll: Grid
long_name: Spacecraft attitude roll angle at DDM sample time
units: radian
_FillValue: -9999.00000
comment: Spacecraft roll angle relative to the orbit frame, in radians at ddm_timestamp_utc
sc_roll: Array of 32 bit Reals [sample = 0..164111]
long_name: Spacecraft attitude roll angle at DDM sample time
units: radian
_FillValue: -9999.00000
comment: Spacecraft roll angle relative to the orbit frame, in radians at ddm_timestamp_utc
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
sc_pitch: Grid
long_name: Spacecraft attitude pitch angle at DDM sample time
units: radian
_FillValue: -9999.00000
comment: Spacecraft pitch angle relative to the orbit frame, in radians at ddm_timestamp_utc
sc_pitch: Array of 32 bit Reals [sample = 0..164111]
long_name: Spacecraft attitude pitch angle at DDM sample time
units: radian
_FillValue: -9999.00000
comment: Spacecraft pitch angle relative to the orbit frame, in radians at ddm_timestamp_utc
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
sc_yaw: Grid
long_name: Spacecraft attitude yaw angle at DDM sample time
units: radian
_FillValue: -9999.00000
comment: Spacecraft yaw angle relative to the orbit frame, in radians at ddm_timestamp_utc
sc_yaw: Array of 32 bit Reals [sample = 0..164111]
long_name: Spacecraft attitude yaw angle at DDM sample time
units: radian
_FillValue: -9999.00000
comment: Spacecraft yaw angle relative to the orbit frame, in radians at ddm_timestamp_utc
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
sc_roll_att: Grid
long_name: Spacecraft attitude roll angle at attitude time
units: radian
_FillValue: -9999.00000
comment: Spacecraft roll angle relative to the orbit frame, in radians at att_timestamp_utc
sc_roll_att: Array of 32 bit Reals [sample = 0..164111]
long_name: Spacecraft attitude roll angle at attitude time
units: radian
_FillValue: -9999.00000
comment: Spacecraft roll angle relative to the orbit frame, in radians at att_timestamp_utc
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
sc_pitch_att: Grid
long_name: Spacecraft attitude pitch angle at attitude time
units: radian
_FillValue: -9999.00000
comment: Spacecraft pitch angle relative to the orbit frame, in radians at att_timestamp_utc
sc_pitch_att: Array of 32 bit Reals [sample = 0..164111]
long_name: Spacecraft attitude pitch angle at attitude time
units: radian
_FillValue: -9999.00000
comment: Spacecraft pitch angle relative to the orbit frame, in radians at att_timestamp_utc
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
sc_yaw_att: Grid
long_name: Spacecraft attitude yaw angle at attitude time
units: radian
_FillValue: -9999.00000
comment: Spacecraft yaw angle relative to the orbit frame, in radians at att_timestamp_utc
sc_yaw_att: Array of 32 bit Reals [sample = 0..164111]
long_name: Spacecraft attitude yaw angle at attitude time
units: radian
_FillValue: -9999.00000
comment: Spacecraft yaw angle relative to the orbit frame, in radians at att_timestamp_utc
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
sc_lat: Grid
long_name: Sub-satellite point latitude
standard_name: latitude
units: degrees_north
_FillValue: -9999.00000
comment: Subsatellite point latitude, in degrees North, at ddm_timestamp_utc
sc_lat: Array of 32 bit Reals [sample = 0..164111]
long_name: Sub-satellite point latitude
standard_name: latitude
units: degrees_north
_FillValue: -9999.00000
comment: Subsatellite point latitude, in degrees North, at ddm_timestamp_utc
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
sc_lon: Grid
long_name: Sub-satellite point longitude
standard_name: longitude
units: degrees_east
_FillValue: -9999.00000
comment: Subsatellite point longitude, in degrees East, at ddm_timestamp_utc
sc_lon: Array of 32 bit Reals [sample = 0..164111]
long_name: Sub-satellite point longitude
standard_name: longitude
units: degrees_east
_FillValue: -9999.00000
comment: Subsatellite point longitude, in degrees East, at ddm_timestamp_utc
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
sc_alt: Grid
long_name: Spacecraft altitude
units: meter
_FillValue: -9999
comment: Spacecraft altitude above WGS-84 ellipsoid, in meters, at ddm_timestamp_utc
sc_alt: Array of 32 bit Integers [sample = 0..164111]
long_name: Spacecraft altitude
units: meter
_FillValue: -9999
comment: Spacecraft altitude above WGS-84 ellipsoid, in meters, at ddm_timestamp_utc
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
commanded_sc_roll: Grid
long_name: Commanded spacecraft attitude roll angle
units: radian
_FillValue: -9999.00000
comment: Commanded spacecraft attitude roll angle, in radians at ddm_timestamp_utc. This value is updated every 10 seconds from the ENG_HI packet
commanded_sc_roll: Array of 32 bit Reals [sample = 0..164111]
long_name: Commanded spacecraft attitude roll angle
units: radian
_FillValue: -9999.00000
comment: Commanded spacecraft attitude roll angle, in radians at ddm_timestamp_utc. This value is updated every 10 seconds from the ENG_HI packet
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
rx_clk_bias: Grid
long_name: GPS receiver clock bias
units: meter
_FillValue: -9999.00000
comment: The receiver clock bias (in seconds) multiplied by the speed of light as reported by the DDMI, interpolated to ddm_timestamp_utc, in meters.
rx_clk_bias: Array of 32 bit Reals [sample = 0..164111]
long_name: GPS receiver clock bias
units: meter
_FillValue: -9999.00000
comment: The receiver clock bias (in seconds) multiplied by the speed of light as reported by the DDMI, interpolated to ddm_timestamp_utc, in meters.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
rx_clk_bias_rate: Grid
long_name: GPS receiver clock bias rate
units: meter s-1
_FillValue: -9999.00000
comment: The receiver clock bias rate (in seconds/second) multiplied by the speed of light as reported by the DDMI, interpolated to ddm_timestamp_utc, in m/s.
rx_clk_bias_rate: Array of 32 bit Reals [sample = 0..164111]
long_name: GPS receiver clock bias rate
units: meter s-1
_FillValue: -9999.00000
comment: The receiver clock bias rate (in seconds/second) multiplied by the speed of light as reported by the DDMI, interpolated to ddm_timestamp_utc, in m/s.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
rx_clk_bias_pvt: Grid
long_name: GPS receiver clock bias at PVT time
units: meter
_FillValue: -9999.00000
comment: The receiver clock bias (in seconds) multiplied by the speed of light as reported by the DDMI at pvt_timestamp_utc, in meters.
rx_clk_bias_pvt: Array of 32 bit Reals [sample = 0..164111]
long_name: GPS receiver clock bias at PVT time
units: meter
_FillValue: -9999.00000
comment: The receiver clock bias (in seconds) multiplied by the speed of light as reported by the DDMI at pvt_timestamp_utc, in meters.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
rx_clk_bias_rate_pvt: Grid
long_name: GPS receiver clock bias rate at PVT time
units: meter s-1
_FillValue: -9999.00000
comment: The receiver clock bias rate (in seconds/second) multiplied by the speed of light as reported by the DDMI, at pvt_timestamp_utc, in m/s.
rx_clk_bias_rate_pvt: Array of 32 bit Reals [sample = 0..164111]
long_name: GPS receiver clock bias rate at PVT time
units: meter s-1
_FillValue: -9999.00000
comment: The receiver clock bias rate (in seconds/second) multiplied by the speed of light as reported by the DDMI, at pvt_timestamp_utc, in m/s.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
lna_temp_nadir_starboard: Grid
long_name: Starboard antenna LNA temperature
units: degree_Celsius
_FillValue: -9999.00000
comment: The temperature of the starboard antenna low noise amplifier at ddm_timestamp_utc, in degrees C.
lna_temp_nadir_starboard: Array of 32 bit Reals [sample = 0..164111]
long_name: Starboard antenna LNA temperature
units: degree_Celsius
_FillValue: -9999.00000
comment: The temperature of the starboard antenna low noise amplifier at ddm_timestamp_utc, in degrees C.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
lna_temp_nadir_port: Grid
long_name: Port Antenna LNA temperature
units: degree_Celsius
_FillValue: -9999.00000
comment: The temperature of the port antenna low noise amplifier at ddm_timestamp_utc, in degrees C.
lna_temp_nadir_port: Array of 32 bit Reals [sample = 0..164111]
long_name: Port Antenna LNA temperature
units: degree_Celsius
_FillValue: -9999.00000
comment: The temperature of the port antenna low noise amplifier at ddm_timestamp_utc, in degrees C.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
lna_temp_zenith: Grid
long_name: Zenith Antenna LNA temperature
units: degree_Celsius
_FillValue: -9999.00000
comment: The temperature of the zenith antenna low noise amplifier at ddm_timestamp_utc, in degrees C.
lna_temp_zenith: Array of 32 bit Reals [sample = 0..164111]
long_name: Zenith Antenna LNA temperature
units: degree_Celsius
_FillValue: -9999.00000
comment: The temperature of the zenith antenna low noise amplifier at ddm_timestamp_utc, in degrees C.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm_end_time_offset: Grid
long_name: DDM end time offset
units: 1e-9 s
_FillValue: -9999
comment: For diagnostic use only. See UM document 148-0372 CYGNSS L1 netCDF Diagnostic Variables for more information.
ddm_end_time_offset: Array of 32 bit Integers [sample = 0..164111]
long_name: DDM end time offset
units: 1e-9 s
_FillValue: -9999
comment: For diagnostic use only. See UM document 148-0372 CYGNSS L1 netCDF Diagnostic Variables for more information.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
bit_ratio_lo_hi_starboard: Grid
long_name: Starboard low/high bit counter ratio
units: 1
_FillValue: -9999.00000
comment: Bin ratio of the of the starboard antenna defined as (plus_1_cnts + minus_1_cnts) / (plus_3_cnts + minus_3_cnts).
bit_ratio_lo_hi_starboard: Array of 32 bit Reals [sample = 0..164111]
long_name: Starboard low/high bit counter ratio
units: 1
_FillValue: -9999.00000
comment: Bin ratio of the of the starboard antenna defined as (plus_1_cnts + minus_1_cnts) / (plus_3_cnts + minus_3_cnts).
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
bit_ratio_lo_hi_port: Grid
long_name: Port low/high bit counter ratio
units: 1
_FillValue: -9999.00000
comment: Bin ratio of the of the port antenna defined as (plus_1_cnts + minus_1_cnts) / (plus_3_cnts + minus_3_cnts).
bit_ratio_lo_hi_port: Array of 32 bit Reals [sample = 0..164111]
long_name: Port low/high bit counter ratio
units: 1
_FillValue: -9999.00000
comment: Bin ratio of the of the port antenna defined as (plus_1_cnts + minus_1_cnts) / (plus_3_cnts + minus_3_cnts).
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
bit_ratio_lo_hi_zenith: Grid
long_name: Zenith low/high bit counter ratio
units: 1
_FillValue: -9999.00000
comment: Bin ratio of the of the zenith antenna defined as (plus_1_cnts + minus_1_cnts) / (plus_3_cnts + minus_3_cnts).
bit_ratio_lo_hi_zenith: Array of 32 bit Reals [sample = 0..164111]
long_name: Zenith low/high bit counter ratio
units: 1
_FillValue: -9999.00000
comment: Bin ratio of the of the zenith antenna defined as (plus_1_cnts + minus_1_cnts) / (plus_3_cnts + minus_3_cnts).
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
bit_null_offset_starboard: Grid
long_name: Starboard bit count null offset
units: 1
_FillValue: -9999.00000
comment: For diagnostic use only. See UM document 148-0372 CYGNSS L1 netCDF Diagnostic Variables for more information.
bit_null_offset_starboard: Array of 32 bit Reals [sample = 0..164111]
long_name: Starboard bit count null offset
units: 1
_FillValue: -9999.00000
comment: For diagnostic use only. See UM document 148-0372 CYGNSS L1 netCDF Diagnostic Variables for more information.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
bit_null_offset_port: Grid
long_name: Port bit count null offset
units: 1
_FillValue: -9999.00000
comment: For diagnostic use only. See UM document 148-0372 CYGNSS L1 netCDF Diagnostic Variables for more information.
bit_null_offset_port: Array of 32 bit Reals [sample = 0..164111]
long_name: Port bit count null offset
units: 1
_FillValue: -9999.00000
comment: For diagnostic use only. See UM document 148-0372 CYGNSS L1 netCDF Diagnostic Variables for more information.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
bit_null_offset_zenith: Grid
long_name: Zenith bit count null offset
units: 1
_FillValue: -9999.00000
comment: For diagnostic use only. See UM document 148-0372 CYGNSS L1 netCDF Diagnostic Variables for more information.
bit_null_offset_zenith: Array of 32 bit Reals [sample = 0..164111]
long_name: Zenith bit count null offset
units: 1
_FillValue: -9999.00000
comment: For diagnostic use only. See UM document 148-0372 CYGNSS L1 netCDF Diagnostic Variables for more information.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
status_flags_one_hz: Grid
long_name: 1 Hz Status Flags
_FillValue: -9999
valid_range: 0, 15
flag_masks: 1, 2, 4, 8
flag_meanings: milky_way_in_zenith_field_of_view sun_in_zenith_field_of_view sub_sat_pt_over_open_ocean sub_sat_pt_lat_ascending
comment: One Hz status flags. These flags apply to all four DDMs. 1 indicates presence of condition. Flag masks: 1 = Milky way in zenith antenna field of view 2 = Sun in zenith antenna field of view 4 = Sub-satellite point over open ocean 8 = Sub-satellite point latitude ascending, i.e. sc_lat has increased since the previous DDM sample
status_flags_one_hz: Array of 32 bit Integers [sample = 0..164111]
long_name: 1 Hz Status Flags
_FillValue: -9999
valid_range: 0, 15
flag_masks: 1, 2, 4, 8
flag_meanings: milky_way_in_zenith_field_of_view sun_in_zenith_field_of_view sub_sat_pt_over_open_ocean sub_sat_pt_lat_ascending
comment: One Hz status flags. These flags apply to all four DDMs. 1 indicates presence of condition. Flag masks: 1 = Milky way in zenith antenna field of view 2 = Sun in zenith antenna field of view 4 = Sub-satellite point over open ocean 8 = Sub-satellite point latitude ascending, i.e. sc_lat has increased since the previous DDM sample
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
prn_code: Grid
long_name: GPS PRN code
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -99
valid_min: 0
valid_max: 32
comment: The PRN code of the GPS signal associated with the DDM. Ranges from 0 to 32. 0 = reflectometry channel idle. 1 through 32 = GPS PRN codes.
prn_code: Array of 16 bit Integers [sample = 0..164111][ddm = 0..3]
long_name: GPS PRN code
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -99
valid_min: 0
valid_max: 32
comment: The PRN code of the GPS signal associated with the DDM. Ranges from 0 to 32. 0 = reflectometry channel idle. 1 through 32 = GPS PRN codes.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
sv_num: Grid
long_name: GPS Space Vehicle Number
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999
comment: The GPS unique space vehicle number that transmitted prn_code.
sv_num: Array of 32 bit Integers [sample = 0..164111][ddm = 0..3]
long_name: GPS Space Vehicle Number
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999
comment: The GPS unique space vehicle number that transmitted prn_code.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
track_id: Grid
long_name: DDM Track ID
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999
comment: A track is a temporally contiguous series of DDMs that have the same prn_code. Each track in the file is assigned a unique track_id starting with one. track_id ranges from 1 to N, where N is the total number of tracks in the file.
track_id: Array of 32 bit Integers [sample = 0..164111][ddm = 0..3]
long_name: DDM Track ID
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999
comment: A track is a temporally contiguous series of DDMs that have the same prn_code. Each track in the file is assigned a unique track_id starting with one. track_id ranges from 1 to N, where N is the total number of tracks in the file.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
ddm_ant: Grid
long_name: DDM Antenna
coordinates: ddm_timestamp_utc sp_lat sp_lon
_FillValue: -99
valid_range: 0, 3
flag_values: 0, 1, 2, 3
flag_meanings: none zenith nadir_starboard nadir_port
comment: The antenna that received the reflected GPS signal associated with the DDM. 0 = none 1 = zenith (never used) 2 = nadir_starboard 3 = nadir_port
ddm_ant: Array of 16 bit Integers [sample = 0..164111][ddm = 0..3]
long_name: DDM Antenna
coordinates: ddm_timestamp_utc sp_lat sp_lon
_FillValue: -99
valid_range: 0, 3
flag_values: 0, 1, 2, 3
flag_meanings: none zenith nadir_starboard nadir_port
comment: The antenna that received the reflected GPS signal associated with the DDM. 0 = none 1 = zenith (never used) 2 = nadir_starboard 3 = nadir_port
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
zenith_code_phase: Grid
long_name: Zenith signal code phase
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: The DDMI-measured code phase of the direct GPS signal for prn_code interpolated to ddm_timestamp_utc. 0 <= zenith_code_phase < 1023.0.
zenith_code_phase: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: Zenith signal code phase
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: The DDMI-measured code phase of the direct GPS signal for prn_code interpolated to ddm_timestamp_utc. 0 <= zenith_code_phase < 1023.0.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
sp_ddmi_delay_correction: Grid
long_name: Correction to DDMI specular point delay
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: For diagnostic use only. See UM document 148-0372 CYGNSS L1 netCDF Diagnostic Variables for more information.
sp_ddmi_delay_correction: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: Correction to DDMI specular point delay
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: For diagnostic use only. See UM document 148-0372 CYGNSS L1 netCDF Diagnostic Variables for more information.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
sp_ddmi_dopp_correction: Grid
long_name: Correction to DDMI specular point Doppler
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: s-1
_FillValue: -9999.00000
comment: For diagnostic use only. See UM document 148-0372 CYGNSS L1 netCDF Diagnostic Variables for more information.
sp_ddmi_dopp_correction: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: Correction to DDMI specular point Doppler
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: s-1
_FillValue: -9999.00000
comment: For diagnostic use only. See UM document 148-0372 CYGNSS L1 netCDF Diagnostic Variables for more information.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
add_range_to_sp: Grid
long_name: Additional range to specular point at DDM sample time
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: For diagnostic use only. See UM document 148-0372 CYGNSS L1 netCDF Diagnostic Variables for more information.
add_range_to_sp: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: Additional range to specular point at DDM sample time
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: For diagnostic use only. See UM document 148-0372 CYGNSS L1 netCDF Diagnostic Variables for more information.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
add_range_to_sp_pvt: Grid
long_name: Additional range to specular point at PVT time
units: 1
_FillValue: -9999.00000
comment: For diagnostic use only. See UM document 148-0372 CYGNSS L1 netCDF Diagnostic Variables for more information.
add_range_to_sp_pvt: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: Additional range to specular point at PVT time
units: 1
_FillValue: -9999.00000
comment: For diagnostic use only. See UM document 148-0372 CYGNSS L1 netCDF Diagnostic Variables for more information.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
sp_ddmi_dopp: Grid
long_name: DDMI Doppler at specular point
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: s-1
_FillValue: -9999.00000
comment: For diagnostic use only. See UM document 148-0372 CYGNSS L1 netCDF Diagnostic Variables for more information.
sp_ddmi_dopp: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: DDMI Doppler at specular point
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: s-1
_FillValue: -9999.00000
comment: For diagnostic use only. See UM document 148-0372 CYGNSS L1 netCDF Diagnostic Variables for more information.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
sp_fsw_delay: Grid
long_name: Flight software specular point delay
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: For diagnostic use only. See UM document 148-0372 CYGNSS L1 netCDF Diagnostic Variables for more information.
sp_fsw_delay: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: Flight software specular point delay
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: For diagnostic use only. See UM document 148-0372 CYGNSS L1 netCDF Diagnostic Variables for more information.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
sp_delay_error: Grid
long_name: Flight software specular point delay error
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: For diagnostic use only. See UM document 148-0372 CYGNSS L1 netCDF Diagnostic Variables for more information.
sp_delay_error: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: Flight software specular point delay error
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: For diagnostic use only. See UM document 148-0372 CYGNSS L1 netCDF Diagnostic Variables for more information.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
sp_dopp_error: Grid
long_name: Flight software specular point Doppler error
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: s-1
_FillValue: -9999.00000
comment: For diagnostic use only. See UM document 148-0372 CYGNSS L1 netCDF Diagnostic Variables for more information.
sp_dopp_error: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: Flight software specular point Doppler error
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: s-1
_FillValue: -9999.00000
comment: For diagnostic use only. See UM document 148-0372 CYGNSS L1 netCDF Diagnostic Variables for more information.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
fsw_comp_delay_shift: Grid
long_name: Flight software DDM compression delay shift
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: For diagnostic use only. See UM document 148-0372 CYGNSS L1 netCDF Diagnostic Variables for more information.
fsw_comp_delay_shift: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: Flight software DDM compression delay shift
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: For diagnostic use only. See UM document 148-0372 CYGNSS L1 netCDF Diagnostic Variables for more information.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
fsw_comp_dopp_shift: Grid
long_name: Flight software DDM compression Doppler shift
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: s-1
_FillValue: -9999.00000
comment: For diagnostic use only. See UM document 148-0372 CYGNSS L1 netCDF Diagnostic Variables for more information.
fsw_comp_dopp_shift: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: Flight software DDM compression Doppler shift
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: s-1
_FillValue: -9999.00000
comment: For diagnostic use only. See UM document 148-0372 CYGNSS L1 netCDF Diagnostic Variables for more information.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
prn_fig_of_merit: Grid
long_name: PRN selection figure of Merit
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -99
comment: The RCG Figure of Merit (FOM) for the DDM. Ranges from 0 through 15.The DDMI selects the four strongest specular points (SP) for DDM production. It ranks the strength of SPs using an antenna RCG map. The map converts the position of the SP in antenna azimuth and declination angles to an RCG FOM. 0 represents the least FOM value. 15 represents the greatest FOM value.
prn_fig_of_merit: Array of 16 bit Integers [sample = 0..164111][ddm = 0..3]
long_name: PRN selection figure of Merit
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -99
comment: The RCG Figure of Merit (FOM) for the DDM. Ranges from 0 through 15.The DDMI selects the four strongest specular points (SP) for DDM production. It ranks the strength of SPs using an antenna RCG map. The map converts the position of the SP in antenna azimuth and declination angles to an RCG FOM. 0 represents the least FOM value. 15 represents the greatest FOM value.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
tx_clk_bias: Grid
long_name: GPS transmitter clock bias
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter
_FillValue: -9999.00000
comment: The GPS spacecraft (sv_num) clock time minus GPS constellation time (in seconds) times the speed of light, in meters.
tx_clk_bias: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: GPS transmitter clock bias
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter
_FillValue: -9999.00000
comment: The GPS spacecraft (sv_num) clock time minus GPS constellation time (in seconds) times the speed of light, in meters.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
sp_lat: Grid
long_name: Specular point latitude
standard_name: latitude
units: degrees_north
_FillValue: -9999.00000
comment: Specular point latitude, in degrees North, at ddm_timestamp_utc
sp_lat: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: Specular point latitude
standard_name: latitude
units: degrees_north
_FillValue: -9999.00000
comment: Specular point latitude, in degrees North, at ddm_timestamp_utc
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
sp_lon: Grid
long_name: Specular point longitude
standard_name: longitude
units: degrees_east
_FillValue: -9999.00000
comment: Specular point longitude, in degrees East, at ddm_timestamp_utc
sp_lon: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: Specular point longitude
standard_name: longitude
units: degrees_east
_FillValue: -9999.00000
comment: Specular point longitude, in degrees East, at ddm_timestamp_utc
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
sp_alt: Grid
long_name: Specular point altitude
standard_name: altitude
units: meter
_FillValue: -9999.00000
comment: Altitude of the specular point relative to the WGS 84 datum in meters, at ddm_timestamp_utc, as calculated on the ground. Note that an approximated DTU10 mean sea surface height model is used to calculate the specular point altitude.
sp_alt: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: Specular point altitude
standard_name: altitude
units: meter
_FillValue: -9999.00000
comment: Altitude of the specular point relative to the WGS 84 datum in meters, at ddm_timestamp_utc, as calculated on the ground. Note that an approximated DTU10 mean sea surface height model is used to calculate the specular point altitude.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
sp_pos_x: Grid
long_name: Specular point position X
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter
_FillValue: -99999999
comment: The X component of the specular point position in the ECEF coordinate system, in meters, at ddm_timestamp_utc, as calculated on the ground.
sp_pos_x: Array of 32 bit Integers [sample = 0..164111][ddm = 0..3]
long_name: Specular point position X
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter
_FillValue: -99999999
comment: The X component of the specular point position in the ECEF coordinate system, in meters, at ddm_timestamp_utc, as calculated on the ground.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
sp_pos_y: Grid
long_name: Specular point position Y
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter
_FillValue: -99999999
comment: The Y component of the specular point position in the ECEF coordinate system, in meters, at ddm_timestamp_utc, as calculated on the ground.
sp_pos_y: Array of 32 bit Integers [sample = 0..164111][ddm = 0..3]
long_name: Specular point position Y
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter
_FillValue: -99999999
comment: The Y component of the specular point position in the ECEF coordinate system, in meters, at ddm_timestamp_utc, as calculated on the ground.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
sp_pos_z: Grid
long_name: Specular point position Z
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter
_FillValue: -99999999
comment: The Z component of the specular point position in the ECEF coordinate system, in meters, at ddm_timestamp_utc, as calculated on the ground.
sp_pos_z: Array of 32 bit Integers [sample = 0..164111][ddm = 0..3]
long_name: Specular point position Z
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter
_FillValue: -99999999
comment: The Z component of the specular point position in the ECEF coordinate system, in meters, at ddm_timestamp_utc, as calculated on the ground.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
sp_vel_x: Grid
long_name: Specular point velocity X
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter s-1
_FillValue: -9999
comment: The X component of the specular point velocity in the ECEF coordinate system, in m/s, at ddm_timestamp_utc, as calculated on the ground.
sp_vel_x: Array of 32 bit Integers [sample = 0..164111][ddm = 0..3]
long_name: Specular point velocity X
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter s-1
_FillValue: -9999
comment: The X component of the specular point velocity in the ECEF coordinate system, in m/s, at ddm_timestamp_utc, as calculated on the ground.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
sp_vel_y: Grid
long_name: Specular point velocity Y
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter s-1
_FillValue: -9999
comment: The Y component of the specular point velocity in the ECEF coordinate system, in m/s, at ddm_timestamp_utc, as calculated on the ground.
sp_vel_y: Array of 32 bit Integers [sample = 0..164111][ddm = 0..3]
long_name: Specular point velocity Y
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter s-1
_FillValue: -9999
comment: The Y component of the specular point velocity in the ECEF coordinate system, in m/s, at ddm_timestamp_utc, as calculated on the ground.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
sp_vel_z: Grid
long_name: Specular point velocity Z
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter s-1
_FillValue: -9999
comment: The Z component of the specular point velocity in the ECEF coordinate system, in m/s, at ddm_timestamp_utc, as calculated on the ground.
sp_vel_z: Array of 32 bit Integers [sample = 0..164111][ddm = 0..3]
long_name: Specular point velocity Z
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter s-1
_FillValue: -9999
comment: The Z component of the specular point velocity in the ECEF coordinate system, in m/s, at ddm_timestamp_utc, as calculated on the ground.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
sp_inc_angle: Grid
long_name: Specular point incidence angle
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: degree
_FillValue: -9999.00000
comment: The specular point incidence angle, in degrees, at ddm_timestamp_utc. This is the angle between the line normal to the Earth's surface at the specular point and the line extending from the specular point to the spacecraft. See UM Doc. 148-0336, CYGNSS Science Data Processing Coordinate Systems Definitions.
sp_inc_angle: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: Specular point incidence angle
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: degree
_FillValue: -9999.00000
comment: The specular point incidence angle, in degrees, at ddm_timestamp_utc. This is the angle between the line normal to the Earth's surface at the specular point and the line extending from the specular point to the spacecraft. See UM Doc. 148-0336, CYGNSS Science Data Processing Coordinate Systems Definitions.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
sp_theta_orbit: Grid
long_name: Specular point orbit frame theta angle
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: degree
_FillValue: -9999.00000
comment: The angle between the orbit frame +Z axis and the line extending from the spacecraft to the specular point, in degrees, at ddm_timestamp_utc. See UM Doc. 148-0336, CYGNSS Science Data Processing Coordinate Systems Definitions.
sp_theta_orbit: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: Specular point orbit frame theta angle
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: degree
_FillValue: -9999.00000
comment: The angle between the orbit frame +Z axis and the line extending from the spacecraft to the specular point, in degrees, at ddm_timestamp_utc. See UM Doc. 148-0336, CYGNSS Science Data Processing Coordinate Systems Definitions.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
sp_az_orbit: Grid
long_name: Specular point orbit frame azimuth angle
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: degree
_FillValue: -9999.00000
comment: Let line A be the line that extends from the spacecraft to the specular point at ddm_timestamp_utc. Let line B be the projection of line A onto the orbit frame XY plane. sp_az_orbit is the angle between the orbit frame +X axis (the velocity vector) and line B, in degrees, at ddm_timestamp_utc. See UM Doc. 148-0336, CYGNSS Science Data Processing Coordinate Systems Definitions.
sp_az_orbit: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: Specular point orbit frame azimuth angle
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: degree
_FillValue: -9999.00000
comment: Let line A be the line that extends from the spacecraft to the specular point at ddm_timestamp_utc. Let line B be the projection of line A onto the orbit frame XY plane. sp_az_orbit is the angle between the orbit frame +X axis (the velocity vector) and line B, in degrees, at ddm_timestamp_utc. See UM Doc. 148-0336, CYGNSS Science Data Processing Coordinate Systems Definitions.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
sp_theta_body: Grid
long_name: Specular point body frame theta angle
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: degree
_FillValue: -9999.00000
comment: The angle between the spacecraft body frame +Z axis and the line extending from the spacecraft to the specular point, in degrees, at ddm_timestamp_utc. See UM Doc. 148-0336, CYGNSS Science Data Processing Coordinate Systems Definitions.
sp_theta_body: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: Specular point body frame theta angle
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: degree
_FillValue: -9999.00000
comment: The angle between the spacecraft body frame +Z axis and the line extending from the spacecraft to the specular point, in degrees, at ddm_timestamp_utc. See UM Doc. 148-0336, CYGNSS Science Data Processing Coordinate Systems Definitions.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
sp_az_body: Grid
long_name: Specular point body frame azimuth angle
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: degree
_FillValue: -9999.00000
comment: Let line A be the line that extends from the spacecraft to the specular point, at ddm_timestamp_utc. Let line B be the projection of line A onto the spacecraft body frame XY plane. sp_az_body is the angle between the spacecraft body frame +X axis and line B, in degrees, at ddm_timestamp_utc. See UM Doc. 148-0336, CYGNSS Science Data Processing Coordinate Systems Definitions.
sp_az_body: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: Specular point body frame azimuth angle
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: degree
_FillValue: -9999.00000
comment: Let line A be the line that extends from the spacecraft to the specular point, at ddm_timestamp_utc. Let line B be the projection of line A onto the spacecraft body frame XY plane. sp_az_body is the angle between the spacecraft body frame +X axis and line B, in degrees, at ddm_timestamp_utc. See UM Doc. 148-0336, CYGNSS Science Data Processing Coordinate Systems Definitions.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
sp_rx_gain: Grid
long_name: Specular point Rx antenna gain
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: dBi
_FillValue: -9999.00000
comment: The receive antenna gain in the direction of the specular point, in dBi, at ddm_timestamp_utc.
sp_rx_gain: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: Specular point Rx antenna gain
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: dBi
_FillValue: -9999.00000
comment: The receive antenna gain in the direction of the specular point, in dBi, at ddm_timestamp_utc.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
gps_eirp: Grid
long_name: GPS effective isotropic radiated power
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: watt
_FillValue: -9999.00000
comment: The estimated effective isotropic RF power (EIRP) of the L1 C/A code signal within ± 1 MHz of the L1 carrier radiated by space vehicle, sv_num, in the direction of the specular point, in Watts, at ddm_timestamp_utc. Variations in GPS transmit power are tracked by the direct signal power measured by the navigation receiver. One second samples are smoothed by a ± 10 second running average.
gps_eirp: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: GPS effective isotropic radiated power
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: watt
_FillValue: -9999.00000
comment: The estimated effective isotropic RF power (EIRP) of the L1 C/A code signal within ± 1 MHz of the L1 carrier radiated by space vehicle, sv_num, in the direction of the specular point, in Watts, at ddm_timestamp_utc. Variations in GPS transmit power are tracked by the direct signal power measured by the navigation receiver. One second samples are smoothed by a ± 10 second running average.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
static_gps_eirp: Grid
long_name: Static GPS effective isotropic radiated power
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: watt
_FillValue: -9999.00000
comment: Heritage version of gps_eirp (v2.1 and earlier) that assumed a static value for the power level of the L1 signal transmitted by the GPS satellite, prior to implementation of dynamic gps_eirp monitoring in August 2018.
static_gps_eirp: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: Static GPS effective isotropic radiated power
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: watt
_FillValue: -9999.00000
comment: Heritage version of gps_eirp (v2.1 and earlier) that assumed a static value for the power level of the L1 signal transmitted by the GPS satellite, prior to implementation of dynamic gps_eirp monitoring in August 2018.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
gps_tx_power_db_w: Grid
long_name: GPS SV transmit power
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: dBW
_FillValue: -9999.00000
comment: Power input to SV Tx antenna. Referenced from the heritage version of gps_eirp (v2.1 and earlier).
gps_tx_power_db_w: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: GPS SV transmit power
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: dBW
_FillValue: -9999.00000
comment: Power input to SV Tx antenna. Referenced from the heritage version of gps_eirp (v2.1 and earlier).
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
gps_ant_gain_db_i: Grid
long_name: GPS SV transmit antenna gain
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: dBi
_FillValue: -9999.00000
comment: SV antenna gain in the direction of the specular point. Referenced from the heritage version of gps_eirp (v2.1 and earlier).
gps_ant_gain_db_i: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: GPS SV transmit antenna gain
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: dBi
_FillValue: -9999.00000
comment: SV antenna gain in the direction of the specular point. Referenced from the heritage version of gps_eirp (v2.1 and earlier).
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
gps_off_boresight_angle_deg: Grid
long_name: GPS off boresight angle
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: degree
_FillValue: -9999.00000
comment: SV antenna off boresight angle in the direction of the specular point
gps_off_boresight_angle_deg: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: GPS off boresight angle
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: degree
_FillValue: -9999.00000
comment: SV antenna off boresight angle in the direction of the specular point
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
ddm_snr: Grid
long_name: DDM signal to noise ratio
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: dB
_FillValue: -9999.00000
comment: 10log(Smax/Navg), where Smax is the maximum value (in raw counts) in a single DDM bin and Navg is the the average per-bin raw noise counts. ddm_snr is in dB, at ddm_timestamp_utc.
ddm_snr: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: DDM signal to noise ratio
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: dB
_FillValue: -9999.00000
comment: 10log(Smax/Navg), where Smax is the maximum value (in raw counts) in a single DDM bin and Navg is the the average per-bin raw noise counts. ddm_snr is in dB, at ddm_timestamp_utc.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
ddm_noise_floor: Grid
long_name: DDM noise floor
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: For non-black-body DDMs: Is equal to the average bin raw counts in the first 45 delay rows of the uncompressed 20 x 128 DDM, in counts, at ddm_timestamp_utc. For black body DDMs: Is equal to the average bin raw counts in all 128 delay rows of the uncompressed 20 x 128 DDM, in counts, at ddm_timestamp_utc.
ddm_noise_floor: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: DDM noise floor
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: For non-black-body DDMs: Is equal to the average bin raw counts in the first 45 delay rows of the uncompressed 20 x 128 DDM, in counts, at ddm_timestamp_utc. For black body DDMs: Is equal to the average bin raw counts in all 128 delay rows of the uncompressed 20 x 128 DDM, in counts, at ddm_timestamp_utc.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
ddm_noise_floor_corrected: Grid
long_name: DDM noise floor corrected
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: The ddm_noise_floor after a correction factor, based on the nadir antenna bin ratio, has been applied.
ddm_noise_floor_corrected: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: DDM noise floor corrected
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: The ddm_noise_floor after a correction factor, based on the nadir antenna bin ratio, has been applied.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
noise_correction: Grid
long_name: DDM noise floor correction factor
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: The correction factor applied with ddm_noise_floor = (ddm_noise_floor_uncorrected*noise_correction).
noise_correction: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: DDM noise floor correction factor
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: The correction factor applied with ddm_noise_floor = (ddm_noise_floor_uncorrected*noise_correction).
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
inst_gain: Grid
long_name: Instrument gain
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: The black body noise counts divided by the sum of the black body power and the instrument noise power, in count/W, at ddm_timestamp_utc.
inst_gain: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: Instrument gain
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: The black body noise counts divided by the sum of the black body power and the instrument noise power, in count/W, at ddm_timestamp_utc.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
lna_noise_figure: Grid
long_name: LNA noise figure
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: dB
_FillValue: -9999.00000
comment: The low noise amplifier (LNA) noise figure, in dB, at ddm_timestamp_utc. Estimated from pre-launch characterization of LNA performance as a function of LNA temperature.
lna_noise_figure: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: LNA noise figure
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: dB
_FillValue: -9999.00000
comment: The low noise amplifier (LNA) noise figure, in dB, at ddm_timestamp_utc. Estimated from pre-launch characterization of LNA performance as a function of LNA temperature.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
rx_to_sp_range: Grid
long_name: Rx to specular point range
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter
_FillValue: -9999
comment: The distance between the CYGNSS spacecraft and the specular point, in meters, at ddm_timestamp_utc.
rx_to_sp_range: Array of 32 bit Integers [sample = 0..164111][ddm = 0..3]
long_name: Rx to specular point range
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter
_FillValue: -9999
comment: The distance between the CYGNSS spacecraft and the specular point, in meters, at ddm_timestamp_utc.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
tx_to_sp_range: Grid
long_name: Tx to specular point range
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter
_FillValue: -9999
comment: The distance between the GPS satellite and the specular point, in meters, at ddm_timestamp_utc.
tx_to_sp_range: Array of 32 bit Integers [sample = 0..164111][ddm = 0..3]
long_name: Tx to specular point range
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter
_FillValue: -9999
comment: The distance between the GPS satellite and the specular point, in meters, at ddm_timestamp_utc.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
tx_pos_x: Grid
long_name: GPS Tx position X
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter
_FillValue: -99999999
comment: The X component of the GPS spacecraft WGS84 reference frame ECEF position, in meters, at ddm_timestamp_utc
tx_pos_x: Array of 32 bit Integers [sample = 0..164111][ddm = 0..3]
long_name: GPS Tx position X
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter
_FillValue: -99999999
comment: The X component of the GPS spacecraft WGS84 reference frame ECEF position, in meters, at ddm_timestamp_utc
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
tx_pos_y: Grid
long_name: GPS Tx position Y
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter
_FillValue: -99999999
comment: The Y component of the GPS spacecraft WGS84 reference frame ECEF position, in meters, at ddm_timestamp_utc
tx_pos_y: Array of 32 bit Integers [sample = 0..164111][ddm = 0..3]
long_name: GPS Tx position Y
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter
_FillValue: -99999999
comment: The Y component of the GPS spacecraft WGS84 reference frame ECEF position, in meters, at ddm_timestamp_utc
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
tx_pos_z: Grid
long_name: GPS Tx position Z
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter
_FillValue: -99999999
comment: The Z component of the GPS spacecraft WGS84 reference frame ECEF position, in meters, at ddm_timestamp_utc
tx_pos_z: Array of 32 bit Integers [sample = 0..164111][ddm = 0..3]
long_name: GPS Tx position Z
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter
_FillValue: -99999999
comment: The Z component of the GPS spacecraft WGS84 reference frame ECEF position, in meters, at ddm_timestamp_utc
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
tx_vel_x: Grid
long_name: GPS Tx velocity X
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter s-1
_FillValue: -9999
comment: The X component of the GPS spacecraft WGS84 reference frame ECEF velocity in meters, at ddm_timestamp_utc
tx_vel_x: Array of 32 bit Integers [sample = 0..164111][ddm = 0..3]
long_name: GPS Tx velocity X
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter s-1
_FillValue: -9999
comment: The X component of the GPS spacecraft WGS84 reference frame ECEF velocity in meters, at ddm_timestamp_utc
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
tx_vel_y: Grid
long_name: GPS Tx velocity Y
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter s-1
_FillValue: -9999
comment: The Y component of the GPS spacecraft WGS84 reference frame ECEF velocity in meters, at ddm_timestamp_utc
tx_vel_y: Array of 32 bit Integers [sample = 0..164111][ddm = 0..3]
long_name: GPS Tx velocity Y
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter s-1
_FillValue: -9999
comment: The Y component of the GPS spacecraft WGS84 reference frame ECEF velocity in meters, at ddm_timestamp_utc
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
tx_vel_z: Grid
long_name: GPS Tx velocity Z
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter s-1
_FillValue: -9999
comment: The Z component of the GPS spacecraft WGS84 reference frame ECEF velocity in meters, at ddm_timestamp_utc
tx_vel_z: Array of 32 bit Integers [sample = 0..164111][ddm = 0..3]
long_name: GPS Tx velocity Z
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter s-1
_FillValue: -9999
comment: The Z component of the GPS spacecraft WGS84 reference frame ECEF velocity in meters, at ddm_timestamp_utc
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
bb_nearest: Grid
long_name: Time to most recent black body reading
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: second
_FillValue: -9999.00000
comment: The time between ddm_timestamp_utc and the ddm_timestamp_utc associated with the closest (in time) black body reading, in signed seconds. A positive value indicates that the black body reading occurred after ddm_timestamp_utc. A negative value indicates that the block body reading occurred before ddm_timestamp_utc.
bb_nearest: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: Time to most recent black body reading
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: second
_FillValue: -9999.00000
comment: The time between ddm_timestamp_utc and the ddm_timestamp_utc associated with the closest (in time) black body reading, in signed seconds. A positive value indicates that the black body reading occurred after ddm_timestamp_utc. A negative value indicates that the block body reading occurred before ddm_timestamp_utc.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
fresnel_coeff: Grid
long_name: Fresnel power reflection coefficient at specular point
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: The SQUARE of the left hand circularly polarized Fresnel electromagnetic voltage reflection coefficient at 1575 MHz for a smooth ocean surface at the specular point location and incidence angle. See UM document 148-0361 Fresnel Coefficient Calculation for more information.
fresnel_coeff: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: Fresnel power reflection coefficient at specular point
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: The SQUARE of the left hand circularly polarized Fresnel electromagnetic voltage reflection coefficient at 1575 MHz for a smooth ocean surface at the specular point location and incidence angle. See UM document 148-0361 Fresnel Coefficient Calculation for more information.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
ddm_nbrcs: Grid
long_name: Normalized BRCS
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: Normalized BRCS of a 3 delay x 5 Doppler bin box that includes the specular point bin. The specular point bin is in the top (least delay) row and the center Doppler column of the 3 x 5 box.
ddm_nbrcs: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: Normalized BRCS
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: Normalized BRCS of a 3 delay x 5 Doppler bin box that includes the specular point bin. The specular point bin is in the top (least delay) row and the center Doppler column of the 3 x 5 box.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
ddm_les: Grid
long_name: Leading edge slope
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: Leading edge slope of a 3 delay x 5 Doppler bin box that include the specular point bin. The specular point bin is in the top (least delay) row and the center Doppler column of the 3 x 5 box.
ddm_les: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: Leading edge slope
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: Leading edge slope of a 3 delay x 5 Doppler bin box that include the specular point bin. The specular point bin is in the top (least delay) row and the center Doppler column of the 3 x 5 box.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
nbrcs_scatter_area: Grid
long_name: NBRCS scattering area
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter2
_FillValue: -9999.00000
comment: The scattering area of the 3 x 5 region of the ddm used to calculate ddm_nbrcs.
nbrcs_scatter_area: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: NBRCS scattering area
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter2
_FillValue: -9999.00000
comment: The scattering area of the 3 x 5 region of the ddm used to calculate ddm_nbrcs.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
les_scatter_area: Grid
long_name: LES scattering area
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter2
_FillValue: -9999.00000
comment: The scattering area of the 3 x 5 region of the ddm used to calculate ddm_les.
les_scatter_area: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: LES scattering area
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter2
_FillValue: -9999.00000
comment: The scattering area of the 3 x 5 region of the ddm used to calculate ddm_les.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
brcs_ddm_peak_bin_delay_row: Grid
long_name: BRCS DDM peak bin delay row
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -99
comment: The zero-based delay row of the peak value in the bistatic radar cross section DDM (brcs). Ranges from 0 to 16.
brcs_ddm_peak_bin_delay_row: Array of 16 bit Integers [sample = 0..164111][ddm = 0..3]
long_name: BRCS DDM peak bin delay row
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -99
comment: The zero-based delay row of the peak value in the bistatic radar cross section DDM (brcs). Ranges from 0 to 16.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
brcs_ddm_peak_bin_dopp_col: Grid
long_name: BRCS DDM peak bin Doppler column
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -99
comment: The zero-based Doppler column of the peak value in the bistatic radar cross section DDM (brcs). Ranges from 0 to 10.
brcs_ddm_peak_bin_dopp_col: Array of 16 bit Integers [sample = 0..164111][ddm = 0..3]
long_name: BRCS DDM peak bin Doppler column
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -99
comment: The zero-based Doppler column of the peak value in the bistatic radar cross section DDM (brcs). Ranges from 0 to 10.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
brcs_ddm_sp_bin_delay_row: Grid
long_name: BRCS DDM specular point bin delay row
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: The zero-based delay row of the specular point delay in the bistatic radar cross section DDM (brcs). Note that this is a floating point value.
brcs_ddm_sp_bin_delay_row: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: BRCS DDM specular point bin delay row
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: The zero-based delay row of the specular point delay in the bistatic radar cross section DDM (brcs). Note that this is a floating point value.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
brcs_ddm_sp_bin_dopp_col: Grid
long_name: BRCS DDM specular point bin Doppler column
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: The zero-based Doppler column of the specular point Doppler in the bistatic radar cross section DDM (brcs). Note that this is a floating point value.
brcs_ddm_sp_bin_dopp_col: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: BRCS DDM specular point bin Doppler column
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: The zero-based Doppler column of the specular point Doppler in the bistatic radar cross section DDM (brcs). Note that this is a floating point value.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
ddm_brcs_uncert: Grid
long_name: DDM BRCS uncertainty
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: Uncertainty of the BRCS
ddm_brcs_uncert: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: DDM BRCS uncertainty
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: Uncertainty of the BRCS
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
bb_power_temperature_density: Grid
long_name: Black Body Power Temperature Density
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: Counts/Kelvin
_FillValue: -9999.00000
comment: Raw counts of detected power radiated by the blackbody calibration target, divided by receiver gain and blackbody physical temperature in Kelvins, gives the detected power per unit absolute temperature.
bb_power_temperature_density: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: Black Body Power Temperature Density
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: Counts/Kelvin
_FillValue: -9999.00000
comment: Raw counts of detected power radiated by the blackbody calibration target, divided by receiver gain and blackbody physical temperature in Kelvins, gives the detected power per unit absolute temperature.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
zenith_sig_i2q2: Grid
long_name: Zenith Signal I2Q2
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: Raw counts of detected power in direct GPS L1 C/A signal received by zenith navigation antenna and detected by navigation receiver.
zenith_sig_i2q2: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: Zenith Signal I2Q2
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: Raw counts of detected power in direct GPS L1 C/A signal received by zenith navigation antenna and detected by navigation receiver.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
zenith_sig_i2q2_corrected: Grid
long_name: Zenith Signal I2Q2 Corrected
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: The zenith_sig_i2q2 after a correction factor, based on the zenith antenna bin ratio, has been applied.
zenith_sig_i2q2_corrected: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: Zenith Signal I2Q2 Corrected
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: The zenith_sig_i2q2 after a correction factor, based on the zenith antenna bin ratio, has been applied.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
zenith_sig_i2q2_mult_correction: Grid
long_name: Zenith Signal I2Q2 Multiplicative Correction Factor
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: The multiplicative correction factor applied with zenith_sig_i2q2_corrected = 10*log10(zenith_sig_i2q2*zenith_sig_i2q2_mult_correction)-zenith_sig_i2q2_add_correction.
zenith_sig_i2q2_mult_correction: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: Zenith Signal I2Q2 Multiplicative Correction Factor
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: The multiplicative correction factor applied with zenith_sig_i2q2_corrected = 10*log10(zenith_sig_i2q2*zenith_sig_i2q2_mult_correction)-zenith_sig_i2q2_add_correction.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
zenith_sig_i2q2_add_correction: Grid
long_name: Zenith Signal I2 Q2 additive correction factor
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: The additive correction factor applied with zenith_sig_i2q2_corrected = 10*log10(zenith_sig_i2q2*zenith_sig_i2q2_mult_correction)-zenith_sig_i2q2_add_correction.
zenith_sig_i2q2_add_correction: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: Zenith Signal I2 Q2 additive correction factor
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: The additive correction factor applied with zenith_sig_i2q2_corrected = 10*log10(zenith_sig_i2q2*zenith_sig_i2q2_mult_correction)-zenith_sig_i2q2_add_correction.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
starboard_gain_setting: Grid
long_name: The Nadir-Starboard Gain Setting
units: dB
_FillValue: -9999
comment: The Nadir-Starboard Gain Setting (dB, 0=Automatic)
starboard_gain_setting: Array of 32 bit Integers [sample = 0..164111]
long_name: The Nadir-Starboard Gain Setting
units: dB
_FillValue: -9999
comment: The Nadir-Starboard Gain Setting (dB, 0=Automatic)
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
port_gain_setting: Grid
long_name: The Nadir-Port Gain Setting
units: dB
_FillValue: -9999
comment: The Nadir-Port Gain Setting (dB, 0=Automatic)
port_gain_setting: Array of 32 bit Integers [sample = 0..164111]
long_name: The Nadir-Port Gain Setting
units: dB
_FillValue: -9999
comment: The Nadir-Port Gain Setting (dB, 0=Automatic)
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm_kurtosis: Grid
long_name: DDM kurtosis
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: The kurtosis of the DDM noise floor. For diagnostic use only. See UM document 148-0347 DDM RFI Algorithm for more information.
ddm_kurtosis: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3]
long_name: DDM kurtosis
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999.00000
comment: The kurtosis of the DDM noise floor. For diagnostic use only. See UM document 148-0347 DDM RFI Algorithm for more information.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
quality_flags: Grid
long_name: Per-DDM quality flags 1
coordinates: ddm_timestamp_utc sp_lat sp_lon
_FillValue: -9999
valid_range: 0, 2147483647
flag_masks: 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536, 131072, 262144, 524288, 1048576, 2097152, 4194304, 8388608, 16777216, 33554432, 67108864, 134217728, 268435456, 536870912, 1073741824
flag_meanings: poor_overall_quality s_band_powered_up small_sc_attitude_err large_sc_attitude_err black_body_ddm ddmi_reconfigured spacewire_crc_invalid ddm_is_test_pattern channel_idle low_confidence_ddm_noise_floor sp_over_land sp_very_near_land sp_near_land large_step_noise_floor large_step_lna_temp direct_signal_in_ddm low_confidence_gps_eirp_estimate rfi_detected brcs_ddm_sp_bin_delay_error brcs_ddm_sp_bin_dopp_error neg_brcs_value_used_for_nbrcs gps_pvt_sp3_error sp_non_existent_error brcs_lut_range_error ant_data_lut_range_error bb_framing_error fsw_comp_shift_error low_quality_gps_ant_knowledge sc_altitude_out_of_nominal_range anomalous_sampling_period invalid_roll_state
comment: First group of the Per-DDM quality flags. 1 indicates presence of condition. More quality flags can be found in quality_flags_2. Flag bit masks: 1/0x00000001 = poor_overall_quality. The logical OR of the following flags. If any one of the following flags are set then poor_overall_quality will be set: large_sc_attitude_err black_body_ddm ddmi_reconfigured spacewire_crc_invalid ddm_is_test_pattern channel_idle low_confidence_ddm_noise_floor sp_over_land sp_very_near_land large_step_noise_floor large_step_lna_temp direct_signal_in_ddm low_confidence_gps_eirp_estimate rfi_detected brcs_ddm_sp_bin_delay_error brcs_ddm_sp_bin_dopp_error gps_pvt_sp3_error sp_non_existent_error brcs_lut_range_error ant_data_lut_range_error bb_framing_error fsw_comp_shift_error low_quality_gps_ant_knowledge sc_altitude_out_of_nominal_range anomalous_sampling_period invalid_roll_state incorrect_ddmi_antenna_selection(quality_flags_2) sp_in_sidelobe(quality_flags_2) fatal_nst_outage(quality_flags_2) low_zenith_ant_gain(quality_flags_2) poor_bb_quality(quality_flags_2) poor_quality_bin_ratio(quality_flags_2) 2/0x00000002 = s_band_powered_up Set if S-band transmitter is powered up. 4/0x00000004 = small_sc_attitude_err Set if the absolute value of the spacecraft roll is between 1 and 30 degrees, the pitch is between 1 and 10 degrees, or the yaw is between 1 and 5 degrees. 8/0x00000008 = large_sc_attitude_err Set if the absolute value of the spacecraft roll is greater than or equal to 30 degrees, the pitch is greater than or equal to 10 degrees, or the yaw is greater than or equal to 5 degrees. 16/0x00000010 = black_body_ddm Set if the black body load was selected during the DDM sampling period. 32/0x00000020 = ddmi_reconfigured Set if the DDMI was reconfigured during the DDM sampling period. 64/0x00000040 = spacewire_crc_invalid Set if the DDM CRC transmitted from the DDMI to the spacecraft computer was not valid. 128/0x00000080 = ddm_is_test_pattern Set if the DDM is a test pattern generated by the DDMI. 256/0x00000100 = channel_idle Set if this reflectometry channel was not tracking a PRN. 512/0x00000200 = low_confidence_ddm_noise_floor Set if the difference between this DDM noise floor and the previous DDM noise floor is greater than 10 percent. 1024/0x00000400 = sp_over_land Set if the specular point is over land. Referenced using a map with 0.1 degree lat/lon bins. Coastline features or islands smaller than bin size may not be properly captured. 2048/0x00000800 = sp_very_near_land Set if the specular point is within 25 km of land. Referenced using a map with 0.1 degree lat/lon bins. 4096/0x00001000 = sp_near_land Set if the specular point is within 50 km of land. Referenced using a map with 0.1 degree lat/lon bins. 8192/0x00002000 = large_step_noise_floor Set if the difference between this DDM noise floor and the previous DDM noise floor is greater than 0.24 dB. 16384/0x00004000 = large_step_lna_temp Set if the LNA temperature rate of change is greater than 1 degree C per minute. 32768/0x00008000 = direct_signal_in_ddm Set if the absolute value of the difference between direct signal code phase and the DDM signal code phase is less than or equal to four. 65536/0x00010000 = low_confidence_gps_eirp_estimate Set when there is low confidence in the GPS effective isotropic radiated power estimate. 131072/0x00020000 = rfi_detected Set when the kurtosis of the DDM noise floor deviates from pure Gaussian by more than 1.0. 262144/0x00040000 = brcs_ddm_sp_bin_delay_error Set if the calculated specular point bin zero-based delay row is less than 4 or greater than 8. 524288/0x00080000 = brcs_ddm_sp_bin_dopp_error Set if the calculated specular point bin zero-based Doppler column is less than 4 or greater than 6. 1048576/0x00100000 = neg_brcs_value_used_for_nbrcs Set if any bin in the 3 x 5 brcs area used to calculate ddm_nbrcs has a negative value. 2097152/0x00200000 = gps_pvt_sp3_error Cannot calculate GPS SV position/velocity/time from SP3 file. 4194304/0x00400000 = sp_non_existent_error Specular point does not exist. 8388608/0x00800000 = brcs_lut_range_error Unable to index into BRCS uncertainty lookup table. 16777216/0x01000000 = ant_data_lut_range_error Unable to index into antenna data lookup table. 33554432/0x02000000 = bb_framing_error Insufficient black body data for calibration. 67108864/0x04000000 = fsw_comp_shift_error Flight software telemetry encoding error of the fsw_comp_delay_shift and fsw_comp_dopp_shift variables. Corrected in FSW version 4.5. 134217728/0x08000000 = low_quality_gps_ant_knowledge Not enough data is available to properly calibrate the NBRCS for this sample's GPS satellite. 268435456/0x10000000 = sc_altitude_out_of_nominal_range The spacecraft's altitude is out of nominal altitude range. Nominal altitude is defined as between 490 km to 550 km. 536870912/0x20000000 = anomalous_sampling_period Set when an anomaly was observed on the CYGNSS or GPS satellite while this sample was taken. These samples have produced data that do not align with typical CYGNSS results. See up to date list at: https://docs.google.com/spreadsheets/d/1AFAZanVGDApLSnJQAAdPfOKoJQs0jnB8ZvIuD1Z5mAc/edit?usp=sharing 1073741824/0x40000000 = invalid_roll_state The spacecraft’s reported roll angle is more than 1 degree from the commanded roll.
quality_flags: Array of 32 bit Integers [sample = 0..164111][ddm = 0..3]
long_name: Per-DDM quality flags 1
coordinates: ddm_timestamp_utc sp_lat sp_lon
_FillValue: -9999
valid_range: 0, 2147483647
flag_masks: 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536, 131072, 262144, 524288, 1048576, 2097152, 4194304, 8388608, 16777216, 33554432, 67108864, 134217728, 268435456, 536870912, 1073741824
flag_meanings: poor_overall_quality s_band_powered_up small_sc_attitude_err large_sc_attitude_err black_body_ddm ddmi_reconfigured spacewire_crc_invalid ddm_is_test_pattern channel_idle low_confidence_ddm_noise_floor sp_over_land sp_very_near_land sp_near_land large_step_noise_floor large_step_lna_temp direct_signal_in_ddm low_confidence_gps_eirp_estimate rfi_detected brcs_ddm_sp_bin_delay_error brcs_ddm_sp_bin_dopp_error neg_brcs_value_used_for_nbrcs gps_pvt_sp3_error sp_non_existent_error brcs_lut_range_error ant_data_lut_range_error bb_framing_error fsw_comp_shift_error low_quality_gps_ant_knowledge sc_altitude_out_of_nominal_range anomalous_sampling_period invalid_roll_state
comment: First group of the Per-DDM quality flags. 1 indicates presence of condition. More quality flags can be found in quality_flags_2. Flag bit masks: 1/0x00000001 = poor_overall_quality. The logical OR of the following flags. If any one of the following flags are set then poor_overall_quality will be set: large_sc_attitude_err black_body_ddm ddmi_reconfigured spacewire_crc_invalid ddm_is_test_pattern channel_idle low_confidence_ddm_noise_floor sp_over_land sp_very_near_land large_step_noise_floor large_step_lna_temp direct_signal_in_ddm low_confidence_gps_eirp_estimate rfi_detected brcs_ddm_sp_bin_delay_error brcs_ddm_sp_bin_dopp_error gps_pvt_sp3_error sp_non_existent_error brcs_lut_range_error ant_data_lut_range_error bb_framing_error fsw_comp_shift_error low_quality_gps_ant_knowledge sc_altitude_out_of_nominal_range anomalous_sampling_period invalid_roll_state incorrect_ddmi_antenna_selection(quality_flags_2) sp_in_sidelobe(quality_flags_2) fatal_nst_outage(quality_flags_2) low_zenith_ant_gain(quality_flags_2) poor_bb_quality(quality_flags_2) poor_quality_bin_ratio(quality_flags_2) 2/0x00000002 = s_band_powered_up Set if S-band transmitter is powered up. 4/0x00000004 = small_sc_attitude_err Set if the absolute value of the spacecraft roll is between 1 and 30 degrees, the pitch is between 1 and 10 degrees, or the yaw is between 1 and 5 degrees. 8/0x00000008 = large_sc_attitude_err Set if the absolute value of the spacecraft roll is greater than or equal to 30 degrees, the pitch is greater than or equal to 10 degrees, or the yaw is greater than or equal to 5 degrees. 16/0x00000010 = black_body_ddm Set if the black body load was selected during the DDM sampling period. 32/0x00000020 = ddmi_reconfigured Set if the DDMI was reconfigured during the DDM sampling period. 64/0x00000040 = spacewire_crc_invalid Set if the DDM CRC transmitted from the DDMI to the spacecraft computer was not valid. 128/0x00000080 = ddm_is_test_pattern Set if the DDM is a test pattern generated by the DDMI. 256/0x00000100 = channel_idle Set if this reflectometry channel was not tracking a PRN. 512/0x00000200 = low_confidence_ddm_noise_floor Set if the difference between this DDM noise floor and the previous DDM noise floor is greater than 10 percent. 1024/0x00000400 = sp_over_land Set if the specular point is over land. Referenced using a map with 0.1 degree lat/lon bins. Coastline features or islands smaller than bin size may not be properly captured. 2048/0x00000800 = sp_very_near_land Set if the specular point is within 25 km of land. Referenced using a map with 0.1 degree lat/lon bins. 4096/0x00001000 = sp_near_land Set if the specular point is within 50 km of land. Referenced using a map with 0.1 degree lat/lon bins. 8192/0x00002000 = large_step_noise_floor Set if the difference between this DDM noise floor and the previous DDM noise floor is greater than 0.24 dB. 16384/0x00004000 = large_step_lna_temp Set if the LNA temperature rate of change is greater than 1 degree C per minute. 32768/0x00008000 = direct_signal_in_ddm Set if the absolute value of the difference between direct signal code phase and the DDM signal code phase is less than or equal to four. 65536/0x00010000 = low_confidence_gps_eirp_estimate Set when there is low confidence in the GPS effective isotropic radiated power estimate. 131072/0x00020000 = rfi_detected Set when the kurtosis of the DDM noise floor deviates from pure Gaussian by more than 1.0. 262144/0x00040000 = brcs_ddm_sp_bin_delay_error Set if the calculated specular point bin zero-based delay row is less than 4 or greater than 8. 524288/0x00080000 = brcs_ddm_sp_bin_dopp_error Set if the calculated specular point bin zero-based Doppler column is less than 4 or greater than 6. 1048576/0x00100000 = neg_brcs_value_used_for_nbrcs Set if any bin in the 3 x 5 brcs area used to calculate ddm_nbrcs has a negative value. 2097152/0x00200000 = gps_pvt_sp3_error Cannot calculate GPS SV position/velocity/time from SP3 file. 4194304/0x00400000 = sp_non_existent_error Specular point does not exist. 8388608/0x00800000 = brcs_lut_range_error Unable to index into BRCS uncertainty lookup table. 16777216/0x01000000 = ant_data_lut_range_error Unable to index into antenna data lookup table. 33554432/0x02000000 = bb_framing_error Insufficient black body data for calibration. 67108864/0x04000000 = fsw_comp_shift_error Flight software telemetry encoding error of the fsw_comp_delay_shift and fsw_comp_dopp_shift variables. Corrected in FSW version 4.5. 134217728/0x08000000 = low_quality_gps_ant_knowledge Not enough data is available to properly calibrate the NBRCS for this sample's GPS satellite. 268435456/0x10000000 = sc_altitude_out_of_nominal_range The spacecraft's altitude is out of nominal altitude range. Nominal altitude is defined as between 490 km to 550 km. 536870912/0x20000000 = anomalous_sampling_period Set when an anomaly was observed on the CYGNSS or GPS satellite while this sample was taken. These samples have produced data that do not align with typical CYGNSS results. See up to date list at: https://docs.google.com/spreadsheets/d/1AFAZanVGDApLSnJQAAdPfOKoJQs0jnB8ZvIuD1Z5mAc/edit?usp=sharing 1073741824/0x40000000 = invalid_roll_state The spacecraft’s reported roll angle is more than 1 degree from the commanded roll.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
quality_flags_2: Grid
long_name: Per-DDM quality flags 2
coordinates: ddm_timestamp_utc sp_lat sp_lon
_FillValue: -9999
valid_range: 0, 1024
flag_masks: 1, 2, 4, 8, 16, 32, 64, 128, 256, 512
flag_meanings: incorrect_ddmi_antenna_selection high_signal_noise noise_floor_cal_error sp_in_sidelobe negligible_nst_outage minor_nst_outage fatal_nst_outage low_zenith_ant_gain poor_bb_quality poor_quality_bin_ratio
comment: Second group of the Per-DDM quality flags. 1 indicates presence of condition. The first group of quality flags can be found in quality_flags. Flag bit masks: 1/0x00000001 = incorrect_ddmi_antenna_selection The wrong (port or starboard) antenna was selected. 2/0x00000002 = high_signal_noise The signal is in the highest noise group, but there are still some OK noise rows. Samples are suspect, but may contain quality data. Flag only used for land applications. 4/0x00000004 = noise_floor_cal_error The signal is off or is very near the top rows of the full DDM. A proper noise floor cannot be computed. Flag only used for land applications. 8/0x00000008 = sp_in_sidelobe The specular point is in the sidelobe causing low confidence in the antenna gain. 16/0x00000010 = negligible_nst_outage Minor star track outage with negligible impact on attitude knowledge 32/0x00000020 = minor_nst_outage Minor star track outage with small but acceptable impact on attitude knowledge 64/0x00000040 = fatal_nst_outage Star track outage with unacceptable impact on attitude knowledge 128/0x00000080 = low_zenith_ant_gain Zenith antenna gain is less than -6 dB 256/0x00000100 = poor_bb_quality The distance between the surrounding BB samples > 1350 seconds OR the absolute value of the time to the nearest BB > 350 seconds. 512/0x00000200 = poor_quality_bin_ratio Bin ratio on the nadir or zenith antenna is associated with degraded performance.
quality_flags_2: Array of 32 bit Integers [sample = 0..164111][ddm = 0..3]
long_name: Per-DDM quality flags 2
coordinates: ddm_timestamp_utc sp_lat sp_lon
_FillValue: -9999
valid_range: 0, 1024
flag_masks: 1, 2, 4, 8, 16, 32, 64, 128, 256, 512
flag_meanings: incorrect_ddmi_antenna_selection high_signal_noise noise_floor_cal_error sp_in_sidelobe negligible_nst_outage minor_nst_outage fatal_nst_outage low_zenith_ant_gain poor_bb_quality poor_quality_bin_ratio
comment: Second group of the Per-DDM quality flags. 1 indicates presence of condition. The first group of quality flags can be found in quality_flags. Flag bit masks: 1/0x00000001 = incorrect_ddmi_antenna_selection The wrong (port or starboard) antenna was selected. 2/0x00000002 = high_signal_noise The signal is in the highest noise group, but there are still some OK noise rows. Samples are suspect, but may contain quality data. Flag only used for land applications. 4/0x00000004 = noise_floor_cal_error The signal is off or is very near the top rows of the full DDM. A proper noise floor cannot be computed. Flag only used for land applications. 8/0x00000008 = sp_in_sidelobe The specular point is in the sidelobe causing low confidence in the antenna gain. 16/0x00000010 = negligible_nst_outage Minor star track outage with negligible impact on attitude knowledge 32/0x00000020 = minor_nst_outage Minor star track outage with small but acceptable impact on attitude knowledge 64/0x00000040 = fatal_nst_outage Star track outage with unacceptable impact on attitude knowledge 128/0x00000080 = low_zenith_ant_gain Zenith antenna gain is less than -6 dB 256/0x00000100 = poor_bb_quality The distance between the surrounding BB samples > 1350 seconds OR the absolute value of the time to the nearest BB > 350 seconds. 512/0x00000200 = poor_quality_bin_ratio Bin ratio on the nadir or zenith antenna is associated with degraded performance.
sample: Array of 32 bit Integers [sample = 0..164111]
long_name: Sample index
units: 1
comment: The netCDF coordinate variable associated with the sample dimension, which enumerates the zero-justified index range of the DDM time instants contained in the file.
ddm: Array of 16 bit Integers [ddm = 0..3]
long_name: DDM reflectometry channel
units: 1
comment: The netCDF coordinate variable associated with variables that are dimensioned by the 4 DDMI reflectometry channels. It enumerates the zero-justified index range of DDM reflectometry channels. Ranges from 0 to 3.
raw_counts: Array of 32 bit Integers [sample = 0..164111][ddm = 0..3][delay = 0..16][doppler = 0..10]
long_name: DDM bin raw counts
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: 1
_FillValue: -9999
comment: 17 x 11 array of DDM bin raw counts These are the uncalibrated power values produced by the DDMI.
power_analog: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3][delay = 0..16][doppler = 0..10]
long_name: DDM bin analog power
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: watt
_FillValue: -9999.00000
comment: 17 x 11 array of DDM bin analog power, Watts. analog_power is the true power that would have been measured by an ideal (analog) power sensor. power_digital is the power measured by the actual 2-bit sensor, which includes quantization effects. power_analog has been corrected for quantization effects.
brcs: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3][delay = 0..16][doppler = 0..10]
long_name: DDM bin bistatic radar cross section
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter2
_FillValue: -9999.00000
comment: 17 x 11 array of DDM bin bistatic radar cross section, m^2. The specular point is located in DDM bin round(brcs_ddm_sp_bin_delay_row), round(brcs_ddm_sp_bin_dopp_col).
eff_scatter: Array of 32 bit Reals [sample = 0..164111][ddm = 0..3][delay = 0..16][doppler = 0..10]
long_name: DDM bin effective scattering area
coordinates: ddm_timestamp_utc sp_lat sp_lon
units: meter2
_FillValue: -9999.00000
comment: 17 x 11 array of DDM bin effective scattering area, m^2. This is an estimate of the true surface scattering area that contributes power to each DDM bin, after accounting for the GPS signal spreading function. It is calculated by convolving the GPS ambiguity function with the surface area that contributes power to a given DDM bin as determined by its delay and Doppler values and the measurement geometry. The specular point bin location matches the specular point bin location in brcs.