This product represents the first full polarimetric Global Navigation Satellite System Reflectometry (GNSS-R) dataset, derived from the Soil Moisture Active Passive (SMAP) mission radar. The main parameters are the normalized Stokes parameters, total power normalized bistatic radar cross section, and reflectivity. The SMAP radar receiver, in bistatic radar configuration, measures the horizontal and vertical components of the Global Positioning System (GPS) signal as it is reflected and scatters from the Earth’s surface. Stokes parameters are computed with these horizontal and vertical polarization measurements. The dataset comprises a full reconstruction of the Earth' surface polarimetric values, with approximately 3,200 observations per day and about 1,200,000 per year.

This enhanced Level-2 (L2) product contains calibrated, geolocated, brightness temperatures acquired by the Soil Moisture Active Passive (SMAP) radiometer during 6:00 a.m. descending and 6:00 p.m. ascending half-orbit passes. This product is derived from SMAP Level-1B (L1B) interpolated antenna temperatures. Backus-Gilbert optimal interpolation techniques are used to extract maximum information from SMAP antenna temperatures and convert them to brightness temperatures, which are posted to the 9 km Equal-Area Scalable Earth Grid, Version 2.0 (EASE-Grid 2.0) in a global cylindrical projection [available as the SPl1CTB_E product]. As of 2021, the data are also posted to the Northern Hemisphere EASE-Grid 2.0, an azimuthal equal-area projection. These 9-km brightness temperatures are then used to retrieve surface soil moisture posted on the 9-km grid [this SPL2SMP_E product].

Provides low resolution (LR) non-time critical (NTC; 60-day latency) measurements of sea surface height anomaly (SSHA), Significant Wave Height (SWH), and Wind Speed. The NTC product is analogous to the Jason-3 GDR product.

Provides reprocessed L2 low resolution (LR) non-time critical (NTC; 60-day latency) altimetry from the Poseidon-4 SAR altimeter on the Sentinel-6A Michael Freilich spacecraft. It contains Sea Surface Height (SSH), Sea Surface Height Anomalies (SSHA) and Significant Wave Height (SWH), along with 1 Hz and 20 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 standard product release provides the geophysical parameters at both 1 and 20 Hz. The S6A NTC product is analogous to the Jason-3 GDR product.

Provides reprocessed L2 high resolution (HR) non-time critical (NTC; 60-day latency) altimetry from the Poseidon-4 SAR altimeter on the Sentinel-6A Michael Freilich spacecraft. It contains Sea Surface Height (SSH), Sea Surface Height Anomalies (SSHA) and Significant Wave Height (SWH), along with 1 Hz and 20 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 standard product release provides the geophysical parameters at both 1 and 20 Hz. The S6A NTC product is analogous to the Jason-3 GDR product.

Provides reprocessed L2 high resolution (HR) non-time critical (NTC; 60-day latency) altimetry from the Poseidon-4 SAR altimeter on the Sentinel-6A Michael Freilich 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 S6A NTC product is analogous to the Jason-3 GDR product.

Provides reprocessed L2 non-time critical (NTC; 60-day latency) geophysical information from the Advanced Microwave Radiometer on the Sentinel-6A Michael Freilich spacecraft including surface type, wind speed, water vapor, brightness temperature, sigma0, wet troposphere, and associated quality flags. The data are interpolated to intervals that correspond to altimetry measurements from the Poseidon-4 SAR to supply the geophysical and environmental corrections for altimetry. The S6A NTC product is analogous to the Jason-3 GDR product.

Provides reprocessed L1B low resolution (LR) non-time critical (NTC; 60-day latency) altimetry data from the Poseidon-4 SAR altimeter on the Sentinel-6A Michael Freilich spacecraft which include the geolocated, fully-calibrated pulse-limited LR power echoes. The S6A NTC product is analogous to the Jason-3 GDR product.

Provides reprocessed L1B high resolution (HR) non-time critical (NTC; 60-day latency) altimetry data from the Poseidon-4 SAR altimeter on the Sentinel-6A Michael Freilich spacecraft which include the geolocated, fully SAR processed and calibrated multi-looked HR Ku-band waveforms. The S6A NTC product is analogous to the Jason-3 GDR product.

Provides reprocessed L1A high resolution (HR) non-time critical (NTC; 60-day latency) altimetry intermediate outputs from the Poseidon-4 SAR altimeter on the Sentinel-6A Michael Freilich spacecraft, which are geo-located bursts of Ku-band echoes (at ~140 Hz) with all instrument calibrations applied and full rate complex waveforms for delay/Doppler or HR processing. The S6A NTC product is analogous to the Jason-3 GDR product.