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 dataset provides Level 1 (L1) polarimetric radar backscattering coefficient (Sigma-0 or S-0), multi-look complex, polarimetrically calibrated, and georeferenced data products from the UAVSAR P-band SAR radar instrument collected over 74 study sites across Alaska, USA, and western Canada. The radar instrument is a fully polarimetric P-band (ultra-high frequency) SAR operating in the 420-440 MHz band. The flight campaigns took place periodically in May-August 2017 onboard a NASA Gulfstream-III aircraft. Each set of products was produced from a data take (i.e., acquisition) of the UAVSAR P-band SAR radar instrument, where one data take is equivalent to one flight line over a site. Two to four data takes were sought for each site, although for some sites as few as one or as many as six are provided. There were a total of 139 data takes over the 74 sites.

The GPM Ground Validation NASA S-band Dual Polarimetric (NPOL) Doppler Radar MC3E dataset was collected by the NASA NPOL radar, which was developed by a research team from Wallops Flight Facility, is a fully transportable and self-contained S-band (10 cm), scanning dual-polarimetric, doppler research radar that collected data nearly continuously during the Midlatitude Continental Convective Clouds Experiment (MC3E) field campaign. The overarching goal was to provide the most complete characterization of convective cloud systems, precipitation, and the environment that has ever been obtained, providing constraints for model cumulus parameterizations and space-based rainfall retrieval algorithms over land that had never before been available. NPOL scanned in high resolution Range Height Indicator (RHI) mode (every 40 sec) and provided measurements of precipitation in liquid, mixed and ice phase. The scanning strategy emphasized vertical structure sampling via RHI and narrow sector-volume data collections. Additional files were processed from the UF files using the Colorado State University (CSU) Hydrometeor Identification Algorithm (HID) providing classification of hydrometeors (e.g. rain, drizzle, hail, ice crystals, wet or dry snow, graupel density). Data was collected from April 11, 2011 through June 3, 2011.

The Polarimetric Scanning Radiometer (PSR) is an airborne microwave imaging radiometer developed and operated by the National Oceanic and Atmospheric Administration (NOAA) Environmental Technology Laboratory. Measurements were taken in regional areas of Alabama, Georgia, and Oklahoma, USA and the Little Washita Watershed of Oklahoma, USA during the Soil Moisture Experiment 2003 (SMEX03).

The Polarimetric Scanning Radiometer (PSR) is an airborne microwave imaging radiometer developed and operated by the National Oceanic and Atmospheric Administration (NOAA) Environmental Technology Laboratory. This data set includes brightness temperature data for the C-band and X-band.

The Polarimetric Scanning Radiometer (PSR) is an airborne microwave imaging radiometer developed and operated by the National Oceanic and Atmospheric Administration (NOAA) Environmental Technology Laboratory. This data set includes brightness temperature data for the C-band and X-band.

This enhanced Level-3 (L3) soil moisture product provides a composite of daily estimates of global land surface conditions retrieved by the Soil Moisture Active Passive (SMAP) radiometer. This product is a daily composite of SMAP Level-2 (L2) soil moisture which is derived from SMAP Level-1C (L1C) interpolated brightness temperatures. Backus-Gilbert optimal interpolation techniques are used to extract 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. As of 2021, the data are also posted to the Northern Hemisphere EASE-Grid 2.0, an azimuthal equal-area projection.

This enhanced Level-3 (L3) soil moisture product provides a composite of daily estimates of global land surface conditions retrieved by the Soil Moisture Active Passive (SMAP) radiometer. This product is a daily composite of SMAP Level-2 (L2) soil moisture which is derived from SMAP Level-1C (L1C) interpolated brightness temperatures. Backus-Gilbert optimal interpolation techniques are used to extract 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. As of 2021, the data are also posted to the Northern Hemisphere EASE-Grid 2.0, an azimuthal equal-area projection.

Notice to Data Users: The documentation for this data set was provided solely by the Principal Investigator(s) and was not further developed, thoroughly reviewed, or edited by NSIDC. Thus, support for this data set may be limited. This data set includes brightness temperature and soil moisture data acquired with the Polarimetric Scanning Radiometer (PSR) instrument, an airborne microwave imaging radiometer developed and operated by the National Oceanic and Atmospheric Administration (NOAA) Environmental Technology Laboratory.

This enhanced Level-3 (L3) soil moisture product provides a composite of daily estimates of global land surface conditions retrieved by the Soil Moisture Active Passive (SMAP) radiometer. This product is a daily composite of SMAP Level-2 (L2) soil moisture which is derived from SMAP Level-1C (L1C) interpolated brightness temperatures. Backus-Gilbert optimal interpolation techniques are used to extract 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. As of 2021, the data are also posted to the Northern Hemisphere EASE-Grid 2.0, an azimuthal equal-area projection.