N: 66.15 S: -66.15 E: 180 W: -180
Description
Provides L2 high resolution (HR) short time critical (STC; 36-hour latency) altimetry from the Poseidon-4 SAR altimeter on the Sentinel-6B spacecraft. It contains Sea Surface Height (SSH), Sea Surface Height Anomalies (SSHA) and Significant Wave Height (SWH), along with 1 Hz Ku-band measurements processed from L1B altimetry including the range, orbital altitude, time, and water vapour. It also includes altimetry corrections, significant wave height and wind-speed from the AMR-C. This release is reduced to exclude the 20 Hz observations that are included in the standard product. The S6B STC product is analogous to the Jason-3 IGDR product.
Product Summary
Citation
Citation is critically important for dataset documentation and discovery. This dataset is openly shared, without restriction, in accordance with the EOSDIS Data Use and Citation Guidance.
Copy Citation
Documents
DATA CITATION GUIDELINES
GENERAL DOCUMENTATION
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_01/altitude | Altitude of the satellite center of mass above the reference ellipsoid (WGS84). | m | int | 2147483647 | N/A | 0.0001 | 1300000 |
| /data_01/altitude_rate | Instantaneous altitude rate of the satellite center of mass with respect to the reference ellipsoid (WGS84) | m/s | int | 2147483647 | N/A | 0.0001 | N/A |
| /data_01/altitude_rate_mean_sea_surface | Instantaneous altitude rate of the satellite center of mass with respect to the mean sea surface | m/s | int | 2147483647 | N/A | 0.0001 | N/A |
| /data_01/amr_rain_flag | Flag indicating if AMR measurement is impacted by rain contamination. | N/A | byte | 127 | N/A | 1 | N/A |
| /data_01/amr_sea_ice_flag | Flag indicating if AMR measurement is impacted by sea ice contamination | N/A | byte | 127 | N/A | 1 | N/A |
| /data_01/amr_surface_type_flag | Flag indicating the validity and type of processing applied to generate the AMR wet troposphere correction (amr_wet_tropo_cor). A value of 0 indicates that open ocean processing is used, a value of 1 indicates coastal processing is used, and a value of 2 indicates that amr_wet_trop_cor is invalid due to land contamination. | N/A | byte | 127 | N/A | 1 | N/A |
| /data_01/amr_wet_tropo_cor | Wet tropospheric correction derived from the on-board radiometer and valid over ocean surfaces only. A wet tropospheric correction must be added (negative value) to the instrument range measurement to correct it for the wet tropospheric delays of the radar pulse. Computed from AMR measurements alone. | m | short | 32767 | N/A | 0.0001 | N/A |
| /data_01/amr_wet_tropo_cor_qual | Quality flag for the radiometer wet troposphere correction computed from AMR data alone. | N/A | byte | 127 | N/A | 1 | N/A |
| /data_01/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_01/climato_use_flag | Flag indicating whether the climatological values from meteorological model (backup solution) have been used or not to compute the atmospheric sigma0 correction (atm_cor_sig0). If not, radiometer data is used. | N/A | byte | 127 | N/A | 1 | N/A |
| /data_01/dac | Combines the high frequency fluctuations of the sea surface topography due to high frequency air pressure and wind effect, and the low-frequency heights from inverted barometer effect (inv_bar_cor). To be added as correction to range measurements. | m | short | 32767 | N/A | 0.0001 | N/A |
| /data_01/dac_type_flag | Flag indicating the type (quality level) of dynamic atmospheric correction files used. If no dynamic correction is available, this field will have the default value (127) and inv_baro_cor instead of dac will be used to compute the sea level anomaly. | N/A | byte | 127 | N/A | 1 | N/A |
| /data_01/delta_ellipsoid_tp_wgs84 | Height difference between TOPEX ellipsoid and WGS84 ellipsoid. To convert heights in this product to be relative to the TOPEX ellipsoid, subtract delta_ellipsoid_tp_wgs84. | m | int | 2147483647 | N/A | 0.0001 | N/A |
| /data_01/depth_or_elevation | Ocean depth (bathymetry) is given as negative values; land elevation as positive values | m | short | 32767 | N/A | 1 | N/A |
| /data_01/distance_to_coast | Distance to the closest coast (negative over land, positive over water bodies) | m | short | 32767 | N/A | 100 | N/A |
| /data_01/geoid | Height of the geoid above the reference ellipsoid (WGS84) computed from the model with a correction to refer the value to the mean tide system i.e. includes the permanent tide (zero frequency). | m | int | 2147483647 | N/A | 0.0001 | N/A |
| /data_01/internal_tide | Internal tide prediction from the HRET model. This only includes the so-called static harmonic components of the waves O1, K1, M2 and S2. It is included in the ocean geophysical corrections applied to the sea surface height anomaly. | m | short | 32767 | N/A | 0.0001 | N/A |
| /data_01/inv_bar_cor | Computed at the altimeter time-tag from the interpolation of 2 meteorological fields that surround the altimeter time-tag. It is provided as an alternative to the dynamic atmospheric correction (dac). Do not apply this correction in addition to the dynamic atmospheric correction (dac). The latency/quality of the input files is indicated by the variable dac_type_cor. | m | short | 32767 | N/A | 0.0001 | N/A |
| /data_01/iono_cor_alt | Ionospheric correction derived from the LR altimeter measurements and valid over ocean and lake surfaces only. A ionospheric correction must be added (negative value) to the instrument range measurement to correct it for the ionospheric delays of the radar pulse | m | short | 32767 | N/A | 0.0001 | N/A |
| /data_01/iono_cor_alt_filtered | Smoothed ionospheric correction derived from the LR altimeter measurements and valid over ocean and lake surfaces only, using an iterative process based on median and Lanczos filtering. A ionospheric correction must be added (negative value) to the instrument range measurement to correct it for the ionospheric delays of the radar pulse | m | short | 32767 | N/A | 0.0001 | N/A |
| /data_01/iono_cor_alt_filtered_nr | Smoothed ionospheric correction derived from the LR altimeter measurements (numerical retracking) and valid over ocean and lake surfaces only, using an iterative process based on median and Lanczos filtering. A ionospheric correction must be added (negative value) to the instrument range measurement to correct it for the ionospheric delays of the radar pulse | m | short | 32767 | N/A | 0.0001 | N/A |
| /data_01/iono_cor_alt_nr | Ionospheric correction derived from the LR altimeter measurements (numerical retracking) and valid over ocean and lake surfaces only. A ionospheric correction must be added (negative value) to the instrument range measurement to correct it for the ionospheric delays of the radar pulse | m | short | 32767 | N/A | 0.0001 | N/A |
| /data_01/ku/atm_cor_sig0 | Two-way atmospheric attenuation to backscatter coefficient (sig0), based either on the radiometer (if available) or atmospheric model (otherwise). See climato_use_flag | dB | short | 32767 | N/A | 0.01 | N/A |
| /data_01/ku/index_first_20hz_measurement | Level 2 record counter of the first 20 Hz elementary measurement used to derive the 1 Hz measurement | 1 | int | 2147483647 | N/A | 1 | N/A |
| /data_01/ku/iono_cor_gim | GIM ionospheric correction, computed from GPS ionospheric data. A ionospheric correction must be added (negative value) to the instrument range measurement to correct it for the ionospheric delays of the radar pulse | m | short | 32767 | N/A | 0.0001 | N/A |
| /data_01/ku/model_instr_cor_range_ocean | Modelled instrumental correction on the altimeter range, extracted from look-up tables. The correction is computed at 1-Hz then applied to 20-Hz estimates. | m | int | 2147483647 | N/A | 0.0001 | N/A |
| /data_01/ku/model_instr_cor_range_ocean_nr | Modelled instrumental correction on the altimeter range from the numerical ocean retracker, extracted from look-up tables. The correction is computed at 1-Hz then applied to 20-Hz estimates. | m | int | 2147483647 | N/A | 0.0001 | N/A |
| /data_01/ku/model_instr_cor_sig0_ocean | Modelled instrumental correction on the backscatter coefficient, extracted from look-up tables. The correction is computed at 1-Hz then applied to 20-Hz estimates. | dB | short | 32767 | N/A | 0.01 | N/A |
| /data_01/ku/model_instr_cor_sig0_ocean_nr | Modelled instrumental correction on the backscatter coefficient from the numerical ocean retracker, extracted from look-up tables. The correction is computed at 1-Hz then applied to 20-Hz estimates. | dB | short | 32767 | N/A | 0.01 | N/A |
| /data_01/ku/model_instr_cor_swh_ocean | Modelled instrumental correction on the significant wave height, extracted from look-up tables. The correction is computed at 1-Hz then applied to 20-Hz estimates. | m | short | 32767 | N/A | 0.001 | N/A |
| /data_01/ku/model_instr_cor_swh_ocean_nr | Modelled instrumental correction on the significant wave height from the numerical ocean retracker, extracted from look-up tables. The correction is computed at 1-Hz then applied to 20-Hz estimates. | m | short | 32767 | N/A | 0.001 | N/A |
| /data_01/ku/net_instr_cor_range_ocean | Sum of all instrumental corrections on the altimeter range: USO drift (L1B range_cor_uso) + internal path delay (L1B range_cor_internal_delay_cal and range_cor_internal_delay_diff) + external path delay (L1B range_cor_external_group_delay) + distance antenna-COG (L1B range_cor_com) + Doppler correction (L2 range_cor_doppler) + modelled instrumental errors correction (L2 model_instr_cor_range_ocean) + system bias | m | int | 2147483647 | N/A | 0.0001 | N/A |
| /data_01/ku/net_instr_cor_range_ocean_nr | Sum of all instrumental corrections on the altimeter range from the numerical ocean retracker: USO drift (L1B range_cor_uso) + internal path delay (L1B range_cor_internal_delay_cal and range_cor_internal_delay_diff) + external path delay (L1B range_cor_external_group_delay) + distance antenna-COG (L1B range_cor_com) + Doppler correction (L2 range_cor_doppler) + modelled instrumental errors correction (L2 model_instr_cor_range_ocean_nr) + system bias | m | int | 2147483647 | N/A | 0.0001 | N/A |
| /data_01/ku/net_instr_cor_sig0_ocean | Sum of all instrumental corrections on the backscatter coefficient: all calibrated instrument gains (L1B power_scaling_to_antenna) + modelled instrumental errors correction (L2 model_instr_cor_sig0_ocean) + system bias. The atmospheric attenuation correction is not included. | dB | short | 32767 | N/A | 0.01 | N/A |
| /data_01/ku/net_instr_cor_sig0_ocean_nr | Sum of all instrumental corrections on the backscatter coefficient from the numerical ocean retracker: all calibrated instrument gains (L1B power_scaling_to_antenna) + modelled instrumental errors correction (L2 model_instr_cor_sig0_ocean_nr) + system bias. The atmospheric attenuation correction is not included. | dB | short | 32767 | N/A | 0.01 | N/A |
| /data_01/ku/net_instr_cor_swh_ocean | Sum of all instrumental corrections on the significant wave height: modelled instrumental errors correction and system bias | m | short | 32767 | N/A | 0.001 | N/A |
| /data_01/ku/net_instr_cor_swh_ocean_nr | Sum of all instrumental corrections on the significant wave height from the numerical ocean retracker: modelled instrumental errors correction and system bias | m | short | 32767 | N/A | 0.001 | N/A |
| /data_01/ku/numtotal_20hz_measurement | Total number of 20 Hz measurements in the 1 Hz time interval [time-0.5s, time+0.5s) | 1 | byte | 127 | N/A | 1 | N/A |
| /data_01/ku/ocean_geo_corrections | Sum of meteorological and geophysical corrections to be applied to SSHA over ocean: altimeter ionospheric correction (iono_cor_alt_filtered) + model dry tropospheric correction at zero altitude (model_dry_tropo_cor_zero_altitude) + radiometer wet tropospheric correction (rad_wet_tropo) + sea state bias correction (sea_state_bias) + solid earth tide height (solid_earth_tide) + geocentric ocean tide height solution 2 (FES) (ocean_tide_sol2) + internal tide (internal_tide) + geocentric pole tide height (pole_tide) + dynamic atmospheric correction (dac, or inv_bar_cor if not available, see dac_type_flag) | m | int | 2147483647 | N/A | 0.0001 | N/A |
| /data_01/ku/ocean_geo_corrections_nr | Sum of meteorological and geophysical corrections to be applied to SSHA from the numerical ocean retracker over ocean: altimeter ionospheric correction (iono_cor_alt_filtered_nr) + model dry tropospheric correction at zero altitude (model_dry_tropo_cor_zero_altitude) + radiometer wet tropospheric correction (rad_wet_tropo) + sea state bias correction (sea_state_bias_nr) + solid earth tide height (solid_earth_tide) + geocentric ocean tide height solution 2 (FES) (ocean_tide_sol2) + internal tide (internal_tide) + geocentric pole tide height (pole_tide) + dynamic atmospheric correction (dac, or inv_bar_cor if not available, see dac_type_flag) | m | int | 2147483647 | N/A | 0.0001 | N/A |
| /data_01/ku/rad_atm_cor_sig0_qual | Quality flag for the radiometer two-way atmospheric correction to the Ku-band backscatter coefficient | N/A | byte | 127 | N/A | 1 | N/A |
| /data_01/ku/range_cor_doppler | Doppler correction computed with respect to the mean sea surface / geoid. It is applied to the altimeter range | m | int | 2147483647 | N/A | 0.0001 | N/A |
| /data_01/ku/range_ocean | Range computed from the ocean retracker. It includes all instrumental corrections from net_instr_cor_range_ocean | m | int | 2147483647 | N/A | 0.0001 | 1300000 |
| /data_01/ku/range_ocean_nr | Range computed from the numerical ocean retracker. It includes all instrumental corrections from net_instr_cor_range_ocean_nr | m | int | 2147483647 | N/A | 0.0001 | 1300000 |
| /data_01/ku/range_ocean_nr_numval | Number of valid 20 Hz measurements used to compute the 1 Hz measurement | 1 | byte | 127 | N/A | 1 | N/A |
| /data_01/ku/range_ocean_nr_qual | Validity flag indicating 'good' or 'bad' measurement of the ocean altimeter range | N/A | byte | 127 | N/A | 1 | N/A |
| /data_01/ku/range_ocean_nr_rms | Standard deviation of 20 Hz measurements. Compression of the 20 Hz measurements is preceded by a detection of outliers. Only valid 20 Hz values are used to compute this 1 Hz measurement. | m | short | 32767 | N/A | 0.0001 | N/A |
| /data_01/ku/range_ocean_numval | Number of valid 20 Hz measurements used to compute the 1 Hz measurement | 1 | byte | 127 | N/A | 1 | N/A |
| /data_01/ku/range_ocean_qual | Validity flag indicating 'good' or 'bad' measurement of the ocean altimeter range | N/A | byte | 127 | N/A | 1 | N/A |
| /data_01/ku/range_ocean_rms | Standard deviation of 20 Hz measurements. Compression of the 20 Hz measurements is preceded by a detection of outliers. Only valid 20 Hz values are used to compute this 1 Hz measurement. | m | short | 32767 | N/A | 0.0001 | N/A |