Soil Moisture Active Passive Data (SMAP)

To review the processing and algorithm history for all versions of SMAP data sets, download the following workbooks which get updated on a periodic basis.

Explaining SMAP Version IDs

Composite Release IDs (CRIDs)

SMAP Level-1 through Level-3 data file names include a Composite Release ID (CRID) that represents changes to any data processing condition that might impact SMAP products. The CRID incorporates algorithm, software, and other parameters involved in data processing. Note: The major version does not necessarily coincide with the CRID major version.

Files are named according to the following convention, with the CRID shown in bold:

SMAP_L1A_RADIOMETER_[Orbit#]_[A/D]_yyyymmddThhmmss_RLVvvv_NNN.[ext]

Where:

Science Version IDs

SMAP Level-4 data file names include a Science Version ID that, like the Composite Release ID for Level-1 through -3 data, represents changes to any data processing condition that might impact SMAP product results.

Files are named similar to the following convention, with the Science Version ID shown in bold:

SMAP_L4_C_MDL_yyyymmddThhmmss_VLMmmm_NNN.[ext]

Where:

Maturity States

There are two categories for all SMAP products: 

• Beta — Indicates data sets using a developing algorithm with updates anticipated.
• Validated — Data sets are upgraded to Validated once the Beta algorithm is verified by the algorithm team and validated by the validation team.

Validation Stages

A stage (1, 2, 3, or 4) may be appended to Validated product maturity codes. The following table that describes the validation stages is based on the guidance provided by the CEOS (2015), Committee on Earth Observation Satellites (CEOS) Working Group on Calibration and Validation (WGCV), the CEOS WGCV Land Products Sub-Group, and can be summarized as follows (Colliander et al. 2021, Appendix A).