N: 66.15 S: -66.15 E: 180 W: -180
Description
The Jason-1 Geophysical Data Records (GDR) contain full accuracy altimeter data to measure sea surface height, with a high precision orbit (accuracy ~1.5 cm). The instruments on Jason-1 make direct observations of the following quantities: altimeter range, significant wave height, ocean radar backscatter cross-section (a measure of wind speed), ionospheric electron content (derived by a simple formula), tropospheric water content, mean sea surface, and position relative to the GPS satellite constellation. The GDR contain all relevant corrections needed to calculate the sea surface height. Sea surface height anomalies calculation and recommended data edit criteria are specified in the Jason-1 GDR User Handbook at https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/jason1/open/L2/gdr_netcdf_e/docs/Handbook_Jason-1_v5.1_April2016.pdf
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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 |
|---|---|---|---|---|---|---|---|
| net_instr_corr_range_c | Sum of distance antenna-COG (cog_corr), USO drift correction (uso_corr), internal path correction (internal_path_delay_corr_c), Doppler correction (doppler_corr_c), modeled instrumental errors correction (modeled_instr_corr_range_c) and system bias. Updated to account for reference plane and internal path delay | m | int | 2147483647 | N/A | 0.0001 | N/A |
| net_instr_corr_range_ku | Sum of distance antenna-COG (cog_corr), USO drift correction (uso_corr), internal path correction (internal_path_delay_corr_ku), Doppler correction (doppler_corr_ku), modeled instrumental errors correction (modeled_instr_corr_range_ku) and system bias. Updated to account for reference plane and internal path delay | m | int | 2147483647 | N/A | 0.0001 | N/A |
| net_instr_corr_sig0_c | Sum of AGC instrumental errors correction, internal calibration correction (internal_corr_sig0_c) and modeled instrumental errors correction (modeled_instr_corr_sig0_c) - system bias not included | dB | short | 32767 | N/A | 0.01 | N/A |
| net_instr_corr_sig0_ku | Sum of AGC instrumental errors correction, internal calibration correction (internal_corr_sig0_ku) and modeled instrumental errors correction (modeled_instr_corr_sig0_ku) - system bias not included | dB | short | 32767 | N/A | 0.01 | N/A |
| net_instr_corr_swh_c | Sum of modeled instrumental errors correction (modeled_instr_corr_swh_c) and system bias | m | short | 32767 | N/A | 0.001 | N/A |
| net_instr_corr_swh_ku | Sum of modeled instrumental errors correction (modeled_instr_corr_swh_ku) and system bias | m | short | 32767 | N/A | 0.001 | N/A |
| number_of_iterations_c | 20 Hz number of iterations of the ocean retracking in C band | count | byte | 127 | N/A | 1 | N/A |
| number_of_iterations_ku | 20 Hz number of iterations of the ocean retracking in Ku band | count | byte | 127 | N/A | 1 | N/A |
| ocean_tide_equil | This value has already been added to the two geocentric ocean tide height values recorded in the product (ocean_tide_sol1 and ocean_tide_sol2). The permanent tide (zero frequency) is not included in this parameter because it is included in the geoid and mean sea surface (geoid, mean_sea_surface). See Jason-1 User Handbook | m | short | 32767 | N/A | 0.0001 | N/A |
| ocean_tide_non_equil | This parameter is computed as a correction to the parameter ocean_tide_equil. This value can be added to ocean_tide_equil (or ocean_tide_sol1, ocean_tide_sol2) so that the resulting value models the total non equilibrium ocean tide height. See Jason-1 User Handbook | m | short | 32767 | N/A | 0.0001 | N/A |
| ocean_tide_sol1 | Solution 1 corresponds to GOT4.10 model. Includes the corresponding loading tide (load_tide_sol1) and equilibrium long-period ocean tide height (ocean_tide_equil). The permanent tide (zero frequency) is not included in this parameter because it is included in the geoid and mean sea surface (geoid, mean_sea_surface). See Jason-1 User Handbook | m | int | 2147483647 | N/A | 0.0001 | N/A |
| ocean_tide_sol2 | Solution 2 corresponds to FES2014 model. Includes the corresponding loading tide (load_tide_sol2) and equilibrium long-period ocean tide height (ocean_tide_equil). The permanent tide (zero frequency) is not included in this parameter because it is included in the geoid and mean sea surface (geoid, mean_sea_surface). See Jason-1 User Handbook | m | int | 2147483647 | N/A | 0.0001 | N/A |
| off_nadir_angle_wf_ku | square of the off nadir angle computed from Ku waveforms | degrees^2 | short | 32767 | N/A | 0.0001 | N/A |
| orb_alt_rate | The reference surface for the orbital altitude rate is the combined mean_sea_surface/geoid surface. It is used to compute the Doppler correction on the altimeter range (doppler_corr_ku, doppler_corr_c) | m/s | short | 32767 | N/A | 0.01 | N/A |
| orb_state_flag_rest | 0 characterizes a mission operations orbit that is computed during a maneuver period, 1 stands for an adjusted mission operations orbit, 2 stands for an extrapolated mission operations orbit, 3 stands for an adjusted (preliminary/precise) orbit, 4 indicates that the (preliminary/precise) orbit is estimated during a maneuver period, 5 indicates that the (preliminary/precise) orbit is interpolated over a tracking data gap, 6 means that the (preliminary/precise) orbit is extrapolated for a duration less than 1 day, 7 means that the (preliminary/precise) orbit is extrapolated for a duration that ranges from 1 day to 2 days, 8 means that the (preliminary/precise) orbit is extrapolated for a duration larger than 2 days, or that the orbit is extrapolated just after a maneuver, 9 stands for the DORIS DIODE navigator orbit. The nominal value is 3 | N/A | byte | 127 | N/A | 1 | N/A |
| peakiness_20hz_c | 20 Hz peakiness on C band waveforms | count | short | 32767 | N/A | 0.001 | N/A |
| peakiness_20hz_ku | 20 Hz peakiness on Ku band waveforms | count | short | 32767 | N/A | 0.001 | N/A |
| pole_tide | See Jason-1 User Handbook | m | short | 32767 | N/A | 0.0001 | N/A |
| qual_alt_1hz_off_nadir_angle_wf_ku | quality flag for 1 Hz altimeter data: off nadir angle from Ku band | N/A | byte | 127 | N/A | 1 | N/A |
| qual_alt_1hz_range_c | quality flag for 1 Hz altimeter data: C band range | N/A | byte | 127 | N/A | 1 | N/A |
| qual_alt_1hz_range_ku | quality flag for 1 Hz altimeter data: Ku band range | N/A | byte | 127 | N/A | 1 | N/A |
| qual_alt_1hz_sig0_c | quality flag for 1 Hz altimeter data: C band backscatter coefficient | N/A | byte | 127 | N/A | 1 | N/A |
| qual_alt_1hz_sig0_ku | quality flag for 1 Hz altimeter data: Ku band backscatter coefficient | N/A | byte | 127 | N/A | 1 | N/A |
| qual_alt_1hz_swh_c | quality flag for 1 Hz altimeter data: C band SWH | N/A | byte | 127 | N/A | 1 | N/A |
| qual_alt_1hz_swh_ku | quality flag for 1 Hz altimeter data: Ku band SWH | N/A | byte | 127 | N/A | 1 | N/A |
| qual_inst_corr_1hz_range_c | quality flag for 1 Hz instrumental correction: C band range | N/A | byte | 127 | N/A | 1 | N/A |
| qual_inst_corr_1hz_range_ku | quality flag for 1 Hz instrumental correction: Ku band range | N/A | byte | 127 | N/A | 1 | N/A |
| qual_inst_corr_1hz_sig0_c | quality flag for 1 Hz instrumental correction: C band backscatter coefficient | N/A | byte | 127 | N/A | 1 | N/A |
| qual_inst_corr_1hz_sig0_ku | quality flag for 1 Hz instrumental correction: Ku band backscatter coefficient | N/A | byte | 127 | N/A | 1 | N/A |
| qual_inst_corr_1hz_swh_c | quality flag for 1 Hz instrumental correction: C band SWH | N/A | byte | 127 | N/A | 1 | N/A |
| qual_inst_corr_1hz_swh_ku | quality flag for 1 Hz instrumental correction: Ku band SWH | N/A | byte | 127 | N/A | 1 | N/A |
| qual_rad_1hz_tb187 | quality flag for 1 Hz radiometer data: 18.7 GHz brightness temperature | N/A | byte | 127 | N/A | 1 | N/A |
| qual_rad_1hz_tb238 | quality flag for 1 Hz radiometer data: 23.8 GHz brightness temperature | N/A | byte | 127 | N/A | 1 | N/A |
| qual_rad_1hz_tb340 | quality flag for 1 Hz radiometer data: 34.0 GHz brightness temperature | N/A | byte | 127 | N/A | 1 | N/A |
| rad_averaging_flag | radiometer along-track averaging flag | N/A | byte | 127 | N/A | 1 | N/A |
| rad_distance_to_land | Shortest distance between nadir sub-satellite point and land | m | int | 2147483647 | N/A | 1 | N/A |
| rad_land_frac_187 | radiometer 18.7 GHz antenna gain weighted land fraction in main beam | % | short | 32767 | N/A | 0.01 | N/A |
| rad_land_frac_238 | radiometer 23.8 GHz antenna gain weighted land fraction in main beam | % | short | 32767 | N/A | 0.01 | N/A |
| rad_land_frac_340 | radiometer 34.0 GHz antenna gain weighted land fraction in main beam | % | short | 32767 | N/A | 0.01 | N/A |
| rad_liquid_water | Should not be used over land. | kg/m^2 | short | 32767 | N/A | 0.01 | N/A |
| rad_rain_flag | See Jason-1 User Handbook. The radiometer rain flag indicates where the radiometer wet troposphere path delay (rad_wet_tropo_corr) is invalid due to rain contamination | N/A | byte | 127 | N/A | 1 | N/A |
| rad_sea_ice_flag | See Jason-1 User Handbook. The radiometer sea ice flag indicates where the radiometer wet troposphere path delay (rad_wet_tropo_corr) is invalid due to sea ice contamination | N/A | byte | 127 | N/A | 1 | N/A |
| rad_state_flag_oper | Side A nominal; Side B redundancy | N/A | byte | 127 | N/A | 1 | N/A |
| rad_surf_type | The radiometer surface type flag is applicable to the radiometer wet troposphere path delays provided by rad_wet_tropo_corr. A value of 0 indicates that open ocean processing is used to compute the path delay, 1 indicates coastal processing is used, and 2 indicates the path delay is invalid due to land | N/A | byte | 127 | N/A | 1 | N/A |
| rad_water_vapor | Should not be used over land. | kg/m^2 | short | 32767 | N/A | 0.1 | N/A |
| rad_wet_tropo_corr | 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 | m | short | 32767 | N/A | 0.0001 | N/A |
| rain_flag | See Jason-1 User Handbook | N/A | byte | 127 | N/A | 1 | N/A |
| range_20hz_c | All instrumental corrections included, i.e. distance antenna-COG (cog_corr), USO drift correction (uso_corr), internal path correction (internal_path_delay_corr_c), Doppler correction (doppler_corr_c), modeled instrumental errors correction (modeled_instr_corr_range_c) and system bias. range_20hz_c updated to account for reference plane and internal path delay | m | float | 1.0E+30 | N/A | 1 | N/A |
| range_20hz_ku | All instrumental corrections included, i.e. distance antenna-COG (cog_corr), USO drift correction (uso_corr), internal path correction (internal_path_delay_corr_ku), Doppler correction (doppler_corr_ku), modeled instrumental errors correction (modeled_instr_corr_range_ku) and system bias. range_20hz updated to account for reference plane and internal path delay | m | float | 1.0E+30 | N/A | 1 | N/A |
| range_c | All instrumental corrections included, i.e. distance antenna-COG (cog_corr), USO drift correction (uso_corr), internal path correction (internal_path_delay_corr_c), Doppler correction (doppler_corr_c), modeled instrumental errors correction (modeled_instr_corr_range_c) and system bias. range_c updated to account for reference plane and internal path delay | m | float | 1.0E+30 | N/A | 1 | N/A |