Data Versions

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.

SMAP Version History Workbook L1-L3 Products

SMAP Version History Workbook L4 Products

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:

Variable

Description

R

Release

L

Launch Indicator (1: SMAP Standard Data)

V

1-Digit CRID Major Version Number

vvv

3-Digit CRID Minor Version Number

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:

Variable

Description

V

Science Version

L

Launch Indicator (b: Beta-quality data, v: Validated data)

M

1-Digit Major Science Version Number

mmm

3-Digit Minor Science Version Number

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, or 3) may be appended to Validated product maturity codes. The following table describes the validation stages.

Validation Stage

Description

Stage 1

Product accuracy is estimated using a small number of independent measurements obtained from selected locations, time periods, and ground-truth/field program efforts.

Stage 2

Product accuracy is assessed over a widely distributed set of locations and time periods via several ground-truth and validation efforts.

Stage 3

Product accuracy is assessed, and the uncertainties in the product are well established via independent measurements made in a systematic and statistically robust way that represents global conditions.