N: 77.6 S: -77.6 E: 180 W: -180
Description
Same as L2_NALT_GDR using predicted values for some auxiliary data, and does not have GIM ionosphere model values. Uses the onboard DORIS orbit ephemeris. Available with latency of < 7 hours. Discrete measurements at nadir for each data downlink, along the ground track. Available in netCDF-4 file format.
This collection is a sub-collection of its parent: https://podaac.jpl.nasa.gov/dataset/SWOT_L2_NALT_OGDR_D
Product Summary
Citation
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Variables
The table below lists the variables contained within a single granule for this dataset. Variables often contain observed or derived geophysical measurements collected from a variety of sources, including remote sensing instruments on satellite and airborne platforms, field campaigns, in situ measurements, and model outputs. The terms variable, parameter, scientific data set, layer, and band have been used across NASA’s Earth science disciplines; however, variable is the designated nomenclature in NASA’s Common Metadata Repository (CMR). Variable metadata attributes such as Name, Description, Units, Data Type, Fill Value, Valid Range, and Scale Factor allow users to efficiently process and analyze the data. The full range of attributes may not be applicable to all variables. Additional information on variable attributes is typically available in the data, user guide, and/or other product documentation.
For questions on a specific variable, please use the Earthdata Forum.
| Name Sort descending | Description | Units | Data Type | Fill Value | Valid Range | Scale Factor | Offset |
|---|---|---|---|---|---|---|---|
| /data_20/alt_state_acq_mode_flag | 8 = autonomous acquisition / tracking, 9 = autonomous DIODE acquisition / tracking, 10 = DIODE + Digital Elevation Model tracking | N/A | byte | 127 | N/A | 1 | N/A |
| /data_20/alt_state_track_trans_flag | 20 Hz altimeter state flag: tracking automatic transition | N/A | byte | 127 | N/A | 1 | N/A |
| /data_20/angle_of_approach_to_coast | Angle of approach to the closest coast. 0 is parallel to the coast with the land on the right. Positive values indicate the satellite is approaching the land. Negative values indicate the satellite is leaving the land. Values close to +/-180 degrees have the land on the left | degrees | short | 32767 | N/A | 0.01 | N/A |
| /data_20/c/ice2_qual | ice-2 retracking quality flag | N/A | byte | 127 | N/A | 1 | N/A |
| /data_20/c/num_iterations_ocean | 20 Hz number of iterations of the ocean retracking in C band | count | byte | 127 | N/A | 1 | N/A |
| /data_20/c/peakiness | 20 Hz peakiness on C band waveforms | 1 | int | 2147483647 | N/A | 0.001 | N/A |
| /data_20/c/range_ice2 | Distance antenna-COG (/data_01/range_cor_cog), USO drift correction (/data_01/range_cor_uso), internal path correction (/data_01/c/range_cor_internal_path), Doppler correction (/data_01/c/range_cor_doppler) and system bias included | m | int | 2147483647 | N/A | 0.0001 | 800000 |
| /data_20/c/range_ocean | All instrumental corrections included, i.e. distance antenna-COG (/data_01/range_cor_cog), USO drift correction (/data_01/range_cor_uso), internal path correction (/data_01/c/range_cor_internal_path), Doppler correction (/data_01/c/range_cor_doppler), modeled instrumental errors correction (/data_01/c/range_cor_ocean_model_instr) and system bias | m | int | 2147483647 | N/A | 0.0001 | 800000 |
| /data_20/c/range_ocean_compression_qual | Map of valid points used to compute the 1 Hz C band altimeter range | N/A | byte | 127 | N/A | 1 | N/A |
| /data_20/c/range_ocog | Distance antenna-COG (/data_01/range_cor_cog), USO drift correction (/data_01/range_cor_uso), internal path correction (/data_01/c/range_cor_internal_path), Doppler correction (/data_01/c/range_cor_doppler) and system bias included | m | int | 2147483647 | N/A | 0.0001 | 800000 |
| /data_20/c/sig0_ice2 | AGC instrumental errors correction and internal calibration correction (/data_01/c/sig0_cor_calibration) included | dB | short | 32767 | N/A | 0.01 | N/A |
| /data_20/c/sig0_leading_edge_ice2 | AGC instrumental errors correction and internal calibration correction (/data_01/c/sig0_cor_calibration) included | dB | short | 32767 | N/A | 0.01 | N/A |
| /data_20/c/sig0_ocean | All instrumental corrections included, excepted the system bias, i.e. AGC instrumental errors correction, internal calibration correction (/data_01/c/sig0_cor_calibration), modeled instrumental errors correction (/data_01/c/sig0_cor_ocean_model_instr) and atmospheric attenuation (sig0_cor_atm) | dB | short | 32767 | N/A | 0.01 | N/A |
| /data_20/c/sig0_ocog | AGC instrumental errors correction and internal calibration correction (/data_01/c/sig0_cor_calibration) included | dB | short | 32767 | N/A | 0.01 | N/A |
| /data_20/c/slope2_ice2 | 20 Hz slope of the second part of the logarithm of the C band trailing edge (ice-2 retracking) | s-1 | int | 2147483647 | N/A | 1 | N/A |
| /data_20/c/swh_ocean | All instrumental corrections included, i.e. modeled instrumental errors correction (/data_01/c/swh_cor_ocean_model_instr) and system bias | m | short | 32767 | N/A | 0.001 | N/A |
| /data_20/index_1hz_measurement | Record counter of the averaged 1 Hz measurement associated to the 20 Hz elementary measurement | N/A | int | 2147483647 | N/A | 1 | N/A |
| /data_20/ku/mqe_ice2 | Mean Quadratic Error between the waveforms samples and the corresponding model samples built from the ice-2 retracking outputs | 1 | int | 2147483647 | N/A | 1.0E-5 | N/A |
| /data_20/ku/num_iterations_adaptive | 20 Hz number of iterations of the adaptive retracking in Ku band | count | short | 32767 | N/A | 1 | N/A |
| /data_20/ku/num_iterations_ocean | 20 Hz number of iterations of the ocean retracking in Ku band | count | byte | 127 | N/A | 1 | N/A |
| /data_20/ku/ocog_qual | OCOG retracking quality flag | N/A | byte | 127 | N/A | 1 | N/A |
| /data_20/ku/off_nadir_angle_wf_ocean | 20 Hz square of the off nadir angle computed from Ku band waveforms | degrees^2 | short | 32767 | N/A | 0.0001 | N/A |
| /data_20/ku/off_nadir_angle_wf_ocean_compression_qual | Map of valid points used to compute the 1 Hz square of the off nadir angle computed from Ku band waveforms | N/A | byte | 127 | N/A | 1 | N/A |
| /data_20/ku/range_adaptive | All instrumental corrections included, i.e. distance antenna-COG (/data_01/range_cor_cog), USO drift correction (/data_01/range_cor_uso), internal path correction (/data_01/ku/range_cor_internal_path), Doppler correction (/data_01/ku/range_cor_doppler) and system bias | m | int | 2147483647 | N/A | 0.0001 | 800000 |
| /data_20/ku/range_ocean_mle3 | All instrumental corrections included, i.e. distance antenna-COG (/data_01/range_cor_cog), USO drift correction (/data_01/range_cor_uso), internal path correction (/data_01/ku/range_cor_internal_path), Doppler correction (/data_01/ku/range_cor_doppler), modeled instrumental errors correction (/data_01/ku/range_cor_ocean_mle3_model_instr) and system bias | m | int | 2147483647 | N/A | 0.0001 | 800000 |
| /data_20/ku/range_ocean_mle3_compression_qual | Map of valid points used to compute the 1 Hz Ku band altimeter range | N/A | byte | 127 | N/A | 1 | N/A |
| /data_20/ku/range_ocog | Distance antenna-COG (/data_01/range_cor_cog), USO drift correction (/data_01/range_cor_uso), internal path correction (/data_01/ku/range_cor_internal_path), Doppler correction (/data_01/ku/range_cor_doppler) and system bias included | m | int | 2147483647 | N/A | 0.0001 | 800000 |
| /data_20/ku/range_seaice | Distance antenna-COG (/data_01/range_cor_cog), USO drift correction (/data_01/range_cor_uso), internal path correction (/data_01/ku/range_cor_internal_path), Doppler correction (/data_01/ku/range_cor_doppler) and system bias included | m | int | 2147483647 | N/A | 0.0001 | 800000 |
| /data_20/ku/seaice_qual | sea-ice retracking quality flag | N/A | byte | 127 | N/A | 1 | N/A |
| /data_20/ku/sig0_adaptive_compression_qual | Map of valid points used to compute the 1 Hz Ku band backscatter coefficient | N/A | byte | 127 | N/A | 1 | N/A |
| /data_20/ku/sig0_ice2 | AGC instrumental errors correction and internal calibration correction (/data_01/ku/sig0_cor_calibration) included | dB | short | 32767 | N/A | 0.01 | N/A |
| /data_20/ku/sig0_ocog | AGC instrumental errors correction and internal calibration correction (/data_01/ku/sig0_cor_calibration) included | dB | short | 32767 | N/A | 0.01 | N/A |
| /data_20/ku/sig0_seaice | AGC instrumental errors correction and internal calibration correction (/data_01/ku/sig0_cor_calibration) included | dB | short | 32767 | N/A | 0.01 | N/A |
| /data_20/ku/sig0_tfmra | AGC instrumental errors correction and internal calibration correction (/data_01/ku/sig0_cor_calibration) included | dB | short | 32767 | N/A | 0.01 | N/A |
| /data_20/ku/slope1_ice2 | 20 Hz slope of the first part of the logarithm of the Ku band trailing edge (ice-2 retracking) | s-1 | int | 2147483647 | N/A | 1 | N/A |
| /data_20/ku/slope2_ice2 | 20 Hz slope of the second part of the logarithm of the Ku band trailing edge (ice-2 retracking) | s-1 | int | 2147483647 | N/A | 1 | N/A |
| /data_20/ku/swh_ocean | All instrumental corrections included, i.e. modeled instrumental errors correction (/data_01/ku/swh_cor_ocean_model_instr) and system bias | m | short | 32767 | N/A | 0.001 | N/A |
| /data_20/ku/swh_ocean_compression_qual | Map of valid points used to compute the 1 Hz Ku band significant waveheight | N/A | byte | 127 | N/A | 1 | N/A |
| /data_20/ku/swh_ocean_mle3 | All instrumental corrections included, i.e. modeled instrumental errors correction (/data_01/ku/swh_cor_ocean_mle3_model_instr) and system bias | m | short | 32767 | N/A | 0.001 | N/A |
| /data_20/ku/swh_ocean_mle3_compression_qual | Map of valid points used to compute the 1 Hz Ku band significant waveheight | N/A | byte | 127 | N/A | 1 | N/A |
| /data_20/latitude | Positive latitude is North latitude, negative latitude is South latitude. See SWOT Nadir Altimeter User Handbook | degrees_north | int | 2147483647 | N/A | 1.0E-6 | N/A |
| /data_20/meteo_measurement_altitude_interp_qual | 0 = interpolation from 4 points; 1 = interpolation from less than 4 points | N/A | byte | 127 | N/A | 1 | N/A |
| /data_20/model_dry_tropo_cor_measurement_altitude | Set at FillValue (for O&IGDR) or computed at precise measurement altitude (for GDR) at the altimeter time-tag from the integration and the interpolation of meteorological fields (surface pressure, orography) and profiles (temperature, humidity) that surround the altimeter time-tag. A dry tropospheric correction must be added (negative value) to the instrument range to correct this range measurement for dry tropospheric range delays of the radar pulse. See SWOT Nadir Altimeter User Handbook | m | short | 32767 | N/A | 0.0001 | N/A |
| /data_20/model_wet_tropo_cor_measurement_altitude | Set at FillValue (for O&IGDR) or computed at precise measurement altitude (for GDR) at the altimeter time-tag from the integration and the interpolation of meteorological fields (surface pressure, orography) and profiles (temperature, humidity) that surround the altimeter time-tag. A wet tropospheric correction must be added (negative value) to the instrument range to correct this range measurement for wet tropospheric range delays of the radar pulse. See SWOT Nadir Altimeter User Handbook | m | short | 32767 | N/A | 0.0001 | N/A |
| /data_20/surface_slope_cor | The surface slope correction model aims to improve the accuracy of mean sea surface topography models as well as marine gravity models. See SWOT Nadir Altimeter User Handbook | m | int | 2147483647 | N/A | 0.0001 | N/A |
| /data_20/time_tai | Time of measurement in seconds in the TAI time scale since 1 Jan 2000 00:00:00 TAI. This time scale contains no leap seconds. The difference (in seconds) with time in UTC is given by the attribute [time:tai_utc_difference] | seconds since 2000-01-01 00:00:00.0 | double | 1.844674407371E+19 | N/A | 1 | N/A |