This level 3 monthly product is generated from the RAMSES (Retrieval Algorithm for Microwave Sounders in Earth Science) II algorithm.The RAMSES II algorithm is a microwave only retrieval algorithm using observations from the NOAA-20 (National Oceanic and Atmospheric Administration) also know as Joint Polar Satellite System (JPSS-1) Advanced Technology Microwave Sounder (ATMS) instrument. The ATMS instrument used for this product is a cross-track scanner with 22 channels in spectral bands from 23 GHz through 183 GHz. The RAMSES II retrieval products contain a variety of geophysical parameters retrieved from ATMS measurements, including profiles of temperature, water in all phases as well as surface properties. The RAMSES II algorithm doesn't have a cloud clearing process and produces all weather retrieval

This monthly one degree latitude by one degree longitude level-3 product starts with level-2 retrieval products with QC values of 0 (best), 1 (good), and 2 (don't use) which are provided for each variable.

This level 3 daily product is generated from the RAMSES (Retrieval Algorithm for Microwave Sounders in Earth Science) II algorithm.The RAMSES II algorithm is a microwave only retrieval algorithm using observations from the NOAA-20 (National Oceanic and Atmospheric Administration) also know as Joint Polar Satellite System (JPSS-1) Advanced Technology Microwave Sounder (ATMS) instrument. The ATMS instrument used for this product is a cross-track scanner with 22 channels in spectral bands from 23 GHz through 183 GHz. The RAMSES II retrieval products contain a variety of geophysical parameters retrieved from ATMS measurements, including profiles of temperature, water in all phases as well as surface properties. The RAMSES II algorithm doesn't have a cloud clearing process and produces all weather retrieval

This daily one degree latitude by one degree longitude level-3 product starts with level-2 retrieval products with QC values of 0 (best), 1 (good), and 2 (don't use) which are provided for each variable.

SMAP Level 1A Radar Receive Only Product Version 3

SMAP Level 1A Radar Receive Only Data Quality Information Version 3

SMAP Level 1A Radar Receive Only Product Metadata Version 3

This Level-2 (L2) soil moisture product provides estimates of land surface conditions retrieved by both the Soil Moisture Active Passive (SMAP) radiometer during 6:00 a.m. descending and 6:00 p.m. ascending half-orbit passes and the Sentinel-1A and -1B radar. SMAP L-band brightness temperatures and Copernicus Sentinel-1 C-band backscatter coefficients are used to derive soil moisture data, which are then resampled to an Earth-fixed, cylindrical 3 km Equal-Area Scalable Earth Grid, Version 2.0 (EASE-Grid 2.0). While the 3 km data product has undergone validation, the 1 km product has not and should be used with caution.

The Level-4 (L4) carbon product (SPL4CMDL) provides global gridded daily estimates of net ecosystem carbon (CO2) exchange derived using a satellite data based terrestrial carbon flux model informed by the following: Soil Moisture Active Passive (SMAP) L-band microwave observations, land cover and vegetation inputs from the Moderate Resolution Imaging Spectroradiometer (MODIS), Visible Infrared Imaging Radiometer Suite (VIIRS), and the Goddard Earth Observing System Model, Version 5 (GEOS-5) land model assimilation system. Parameters are computed using an Earth-fixed, global cylindrical 9 km Equal-Area Scalable Earth Grid, Version 2.0 (EASE-Grid 2.0) projection.

This Level-2 (L2) soil moisture product provides estimates of global land surface conditions retrieved by the Soil Moisture Active Passive (SMAP) passive microwave radiometer during 6:00 a.m. descending and 6:00 p.m. ascending half-orbit passes. SMAP L-band brightness temperatures are resampled to an Earth-fixed, global, cylindrical 36 km Equal-Area Scalable Earth Grid, Version 2.0 (EASE-Grid 2.0) [and made available as the SPL1CTB product], and the gridded brightness temperatures are then used to derive gridded soil moisture data.

This Level-1C (L1C) product contains calibrated and 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 L-band Level-1B time-ordered brightness temperatures resampled to an Earth-fixed, 36 km Equal-Area Scalable Earth Grid, Version 2.0 (EASE-Grid 2.0) in three projections: global cylindrical, Northern Hemisphere azimuthal, and Southern Hemisphere azimuthal. This L1C product is a gridded version of the SMAP time-ordered Level-1B radiometer brightness temperature product.

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.