Data Versions

This page provides details of the processing and algorithm history for all versions of SMAP data sets. For an explanation of notations and version naming conventions, refer to the Naming Conventions section of this page.

SMAP On-Orbit Events

For a list of events on the SMAP spacecraft or instrument that may have resulted in missing or incomplete data on certain days, visit the SMAP On-Orbit Events List for Instrument Data Users page.

SMAP L1A Radiometer Time-Ordered Parsed Telemetry (SPL1AP)

Major Version Composite Release ID Maturity State Temporal Coverage Version Changes Date Implemented
Version 1
 
R11850 Beta 2015-03-31 (16:28) to 2015-09-09 (06:18) First public data release 2015-07-31
Version 1
 
R11920 Beta 2015-09-09 (06:14) to 2015-10-26 (18:49) No science change. Minor version incremented to coincide with release of SPL2SMP V1 Beta and V1 SPL3SMP Beta data. 2015-09-09
Version 2
 
R12170 Validated-Stage 2 2015-03-31 (16:28) to 2015-12-15 (03:37) 

Changes to this version include:

  • Transitioned to Validated-Stage 2
  • Calibration parameters were adjusted to reduce calibration jumps and drift previously present in the Beta-release; as a result, calibration now meets its less than 0.4 K/month stability back to 31 March 2015
  • Additional bit-error checking was performed on Level-0 instrument telemetry
2015-10-30
Version 2
 
R12240 Validated-Stage 2 2015-12-17 (18:52) to 2016-01-06 (19:36)  No science change. Minor version incremented to coincide with changes made for radar and SPL2SMP processing. 2015-12-16
Version 2
 
R12241 Validated-Stage 2 2016-01-06 (19:32) to 2016-04-21 (05:16) No science change. Minor version incremented to coincide with changes made to the radiometer reflector table for SPL1BTB V2 and SPL1CTB V2. 2016-01-06
Version 2 R12080 Validated-Stage 2 2016-04-21 (05:12) to present No science change. Minor version incremented to coincide with the Version 3 release of L1B through L3 products.  2016-04-21

SMAP L1B Radiometer Half-Orbit Time-Ordered Brightness Temperatures (SPL1BTB)

Major Version Composite Release ID Maturity State Temporal Coverage Version Changes Date Implemented
Version 1 R11850 Beta (ReportPDF Icon) 2015-03-31 (16:28) to 2015-09-09 (06:18) First public data release 2015-07-31
Version 1
 
R11920 Beta (ReportPDF Icon) 2015-09-09 (21:00) to 2015-10-26 (15:32) Minor version incremented to coincide with release of SPL2SMP Beta and SPL3SMP Beta data. 2015-09-09
Version 2
 
R12170 Validated-Stage 1 (ReportPDF Icon) 2015-03-31 (16:29) to present

Changes to this version include:

  • Transitioned to Validated-Stage 1
  • Using SPL1BTB V2 data as input, inherited all changes and improvements of the new version
2015-10-30
Version 2
 
R12240 Validated-Stage 2 (ReportPDF Icon) 2015-12-17 (18:52) to 2015-12-31 (23:18) No science change. Minor version incremented to coincide with changes made for radar and SPL2SMP processing. 2015-12-16
Version 2
 
R12241 Validated-Stage 2 (ReportPDF Icon) 2015-12-31 (23:14) to 2016-04-21 (06:02) Updated the radiometer reflector table to include the expected temperatures for the radome and reflector for 2016. 2016-01-06
Version 3
 
R13080 Validated-Stage 2 (ReportPDF Icon) 2015-03-31 (16:28) to present Changes to this version include:
  • Updated reflector thermal model
  • Reflector emissivity value back to baseline
  • All calibration coefficients updated back to 3/31/15
  • Direct Galaxy quality flag changed: set when s/c nadir > 5 degrees
  • Reflected Sun quality flag changed: set when specular solar theta <15 degrees
  • Sea ice fraction computation implemented
2016-04-21

SMAP L1C Radiometer Half-Orbit 36 km EASE-Grid Brightness Temperatures (SPL1CTB)

Major Version Composite Release ID Maturity State Temporal Coverage Version Changes Date Implemented
Version 1
 
R11850 Beta (ReportPDF Icon) 2015-03-31 (16:29) to 2015-09-09 (21:04) First public data release 2015-07-31
Version 1
 
R11920 Beta (ReportPDF Icon) 2015-09-09 (21:00) to 2015-10-26 (15:32) No science change. Minor version incremented to coincide with release of SPL2SMP V1 Beta and SPL3SMP V1 Beta data. 2015-09-09
Version 2
 
R12170 Validated-Stage 2 (ReportPDF Icon) 2015-03-31 (16:29) to 2015-12-15 (03:37)

Changes to this version include:

  • Transitioned to Validated-Stage 2
  • Using SPL1BTB V2 Validated data as input, inherited all changes and improvements of the new version
2015-10-30
Version 2
 
R12240 Validated-Stage 2 (ReportPDF Icon) 2015-12-17 (18:52) to 2015-12-31 (23:18) No science change. Minor version incremented to coincide with changes made for radar and SPL2SMP processing. 2015-12-16
Version 2
 
R12241 Validated-Stage 2 (ReportPDF Icon) 2015-12-31 (23:14) to 2016-04-21 (06:02) Updated the radiometer reflector table to include the expected temperatures for the radome and reflector for 2016. 2016-01-06
Version 3
 
R13080 Validated-Stage 2 (ReportPDF Icon) 2015-03-31 (16:28) to present Changes to this version include:
  • Uses updated SPL1BTB V3 Validated data as input
  • Updated processing to produce SPL1CTB data files when partial half-orbit input files are present
2016-04-21

SMAP Enhanced L1C Radiometer Half-Orbit 9 km EASE-Grid Brightness Temperatures (SPL1CTB_E)

Major Version Composite Release ID Maturity State Temporal Coverage Version Changes Date Implemented
Version 1
 
R14010 (ReportPDF Icon) Validated-Stage1 2015-03-31 (16:28) to present First public data release 2016-12-07

SMAP L2 Radiometer Half-Orbit 36 km EASE-Grid Soil Moisture (SPL2SMP)

Major Version Composite Release ID Maturity State Temporal Coverage Version Changes Date Implemented
Version 1
 
R11920 Beta (ReportPDF Icon) 2015-09-09 (21:49) to 2015-10-25 (18:12) First public data release 2015-09-09
Version 2
 
R12170 Beta (ReportPDF Icon) 2015-03-31 (17:18) to 2015-12-15 (03:37)

Changes to this version include:

  • Uses SPL1CTB V2 Validated-Stage 1 data as input
  • Corrects the retrieval quality flag error
2015-10-30
Version 2
 
R12240 Beta (ReportPDF Icon)

2015-12-17 (18:52) to 2015-12-31 (23:18)

Changes to input data processing to use the previous day's snow file if the current day is not available. 2015-12-16
Version 2
 
R12241 Beta (ReportPDF Icon) 2016-01-01 (00:03) to 2016-04-21 (00:21) No science change. Minor version incremented to coincide with an update to the radiometer reflector table SPL1BTB V2 and SPL1CTB V2. 2016-01-06
Version 3
 
R13080 Validated-Stage 2
(ReportPDF Icon)
2015-03-31 (16:28) to present

Changes to this version include:

  • Transitioned to Validated-Stage 2
  • Uses updated SPL1CTB V3 Validated data as input
2016-04-21
Version 4
 
R14010 Validated-Stage 3 (ReportPDF Icon)
 
2015-03-31 (16:28) to present

Changes to this version include:

  • Added 6:00 p.m. ascending half orbits, which provide:
    • More frequent regional/global coverage (critical in flood monitoring)
    • Soil moisture diurnal variability information (useful in data assimilation systems)
    • Consistency with other similar satellite-based soil moisture products
  • Contains frozen ground flag (bit 7 of surface_flag) derived using Normalized Polarization Ration (NPR)-based SMAP passive freeze-thaw retrieval; replaces former SMAP radar-based freeze/thaw flag
2016-12-07

SMAP Enhanced L2 Radiometer Half-Orbit 9 km EASE-Grid Soil Moisture (SPL2SMP_E)

Major Version Composite Release ID Maturity State Temporal Coverage Version Changes Date Implemented
Version 1
 
R14010 (ReportPDF Icon) Validated-Stage 3 2015-03-31 (16:28) to present First public data release 2016-12-07

SMAP L3 Radiometer Global Daily 36 km EASE-Grid Soil Moisture (SPL3SMP)

Major Version Composite Release ID Maturity State Temporal Coverage Version Changes Date Implemented
Version 1
 
R11920 Beta (ReportPDF Icon) 2015-09-10 (00:00) to 2015-10-24 (23:59) First public data release 2015-09-09
Version 2
 
R12170 Beta (ReportPDF Icon) 2015-03-31 (00:00) to

2015-12-15 (23:59)

Changes to this version include:

  • Uses updated SPL1CTB SPL2SMP V2 Beta data as input
  • Corrects the retrieval quality flag error
2015-10-30
Version 2
 
R12240 Beta (ReportPDF Icon) 2015-12-17 (00:00) to 2015-12-31 (23:59) Change to the SPL2SMP V2 input data to use the previous day's snow file if the current day is not available. 2015-12-16
Version 2
 
R12241 Beta (ReportPDF Icon) 2016-01-01 (00:00) to 2016-04-20 (23:59) No science change. Minor version incremented to coincide with an update to the radiometer reflector table SPL1BTB V2 and SPL1CTB V2. 2015-01-06
Version 3
 
R13080 Validated-Stage 2
(ReportPDF Icon)
2015-03-31 (00:00) to present Changes to this version include:
  • Transitioned to Validated-Stage 2
  • Uses updated SPL2SMP V3 Validated data as input version
2016-04-21
Version 4
 
R14010 Validated-Stage 3 (ReportPDF Icon)
 
2015-03-31 (16:28) to present

Changes to this version include:

  • Added 6:00 p.m. ascending half orbits, which provide:
    • More frequent regional/global coverage (critical in flood monitoring)
    • Soil moisture diurnal variability information (useful in data assimilation systems)
    • Consistency with other similar satellite-based soil moisture products
  • Contains frozen ground flag (bit 7 of surface_flag) derived using Normalized Polarization Ration (NPR)-based SMAP passive freeze-thaw retrieval; replaces former SMAP radar-based freeze/thaw flag
2016-12-07

SMAP Enhanced L3 Radiometer Global Daily 9 km EASE-Grid Soil Moisture (SPL3SMP_E)

Major Version Composite Release ID Maturity State Temporal Coverage Version Changes Date Implemented
Version 1
 
R14010 (ReportPDF Icon) Validated-Stage 3 2015-03-31 (16:28) to present First public data release 2016-12-07

SMAP L2 Radar Half-Orbit 3 km EASE-Grid Soil Moisture (SPL2SMA)

Major Version Composite Release ID Maturity State Temporal Coverage Version Changes Date Implemented
Version 2
 
R12170 Beta (ReportPDF Icon) 2015-04-24 (17:19) to 2015-07-07 (00:19) First public data release 2015-11-03
Version 2
 
R12240 Beta (ReportPDF Icon) 2015-04-13 (00:42) to 2015-04-24 (16:32)

This version incorporates a radar calibration update to process data for 13-23 April 2015.

2016-01-13
Version 3
 
R13080 Validated-Stage 1 (ReportPDF Icon) 2015-04-13 (18:45) to 2015-07-07 (00:19) Changes to this version include:
  • Transitioned to Validated-Stage 1
  • Uses updated SPL1CS0 V3 as input
  • Updates to some of the data cubes
  • Update of crop database
  • Modified iterative bias correction
  • Estimation of VWC
2016-04-21

SMAP L3 Radar Global Daily 3 km EASE-Grid Soil Moisture (SPL3SMA)

Major Version Composite Release ID Maturity State Temporal Coverage Version Changes Date Implemented
Version 2
 
R12170 Beta (ReportPDF Icon) 2015-04-25 (00:00) to 2015-07-07 (23:59) First public data release 2015-11-03
Version 2
 
R12240 Beta (ReportPDF Icon) 2015-04-13 (00:00) to 2015-04-24 (23:59)

This version incorporates a radar calibration update to process data for 13-23 April 2015.

2016-01-13
Version 3
 
R13080 Validated-Stage 1 (ReportPDF Icon) 2015-04-13 (00:00) to 2015-07-07 (23:59) Changes to this version include:
  • Transitioned to Validated-Stage 1
  • Uses SPL2SMA V3 Validated data as input; inherited all changes and improvements of the new version
2016-04-21

SMAP L2 Radar/Radiometer Half-Orbit 9 km EASE-Grid Soil Moisture (SPL2SMAP)

Major Version Composite Release ID Maturity State Temporal Coverage Version Changes Date Implemented
Version 2
 
R12170 Beta (ReportPDF Icon) 2015-04-24 (17:18) to 2015-07-07 (00:20) First public data release 2015-11-03
Version 2
 
R12240 Beta (ReportPDF Icon) 2015-04-13 (00:41) to 2015-04-24 (16:33)

This version incorporates a radar calibration update to process data for 13-23 April 2015

2016-01-13
Version 3
 
R13080 Validated-Stage 2 (ReportPDF Icon) 2015-04-13 (18:44) to 2015-07-07 (00:20) Changes to this version include:
  • Transitioned to Validated-Stage 2
  • Uses SPL2SMA V3 Validated and SPL2SMP V3 Validated as input
  • Snapshot beta parameter estimation
  • Updated soil texture files (renormalized cases where sand+clay > 100%)
  • Updated default beta parameter
2016-04-21

SMAP L3 Radar/Radiometer Global Daily 9 km EASE-Grid Soil Moisture (SPL3SMAP)

Major Version Composite Release ID Maturity State Temporal Coverage Version Changes Date Implemented
Version 2
 
R12170 Beta (ReportPDF Icon) 2015-04-25 (00:00) to 2015-07-07 (23:59) First public data release 2015-11-03
Version 2
 
R12240 Beta (ReportPDF Icon) 2015-04-13 (00:00) to 2015-04-24 (23:59)

This version incorporates a radar calibration update to process data for 13-23 April 2015

2016-01-13
Version 3
 
R13080 Validated-Stage 2 (ReportPDF Icon) 2015-04-13 (00:00) to 2015-07-07 (23:59) Changes to this version include:
  • Transitioned to Validated-Stage 2
  • Using SPL2SMAP V3 Validated data as input
2016-04-21

SMAP L3 Radar Northern Hemisphere Daily 3 km EASE-Grid Freeze/Thaw State (SPL3FTA)

Major Version Composite Release ID Maturity State Temporal Coverage Version Changes Date Implemented
Version 2
 
R12170 Beta (ReportPDF Icon) 2015-04-24 (00:00) to 2015-07-07 (23:59) First public data release 2015-11-03
Version 2
 
R12240 Beta (ReportPDF Icon) 2015-04-13 (00:00) to 2015-04-24 (23:59)

This version incorporates a radar calibration update to process data for 13-23 April 2015.

2016-01-13
Version 3
 
R13080 Validated-Stage 2
(ReportPDF Icon)
2015-04-13 (00:00) to 2015-07-07 (23:59) Changes to this version include:
  • Transitioned to Validated-Stage 2
  • Uses SPL1CS0 V3 Validated data as input
  • Using full swath except for nadir-anomaly flagged areas to provide better coverage
  • Resolved some flag and fillValue errors
2016-04-21

SMAP L3 Radiometer Northern Hemisphere Daily 36 km EASE-Grid Freeze/Thaw State (SPL3FTP)

Major Version Composite Release ID Maturity State Temporal Coverage Version Changes Date Implemented
Version 1
 
R14010 Validated-Stage 3 (ReportPDF Icon) 2015-03-31 (16:28) to present First public data release 2016-12-07

SMAP Enhanced L3 Radiometer Northern Hemisphere Daily 9 km EASE-Grid Freeze/Thaw State (SPL3FTP_E)

Major Version Composite Release ID Maturity State Temporal Coverage Version Changes Date Implemented
Version 1
 
R14010

Validated-Stage 3 (ReportPDF Icon)

2015-03-31 (16:28) to present First public data release 2016-12-07

SMAP L4 Global 3-hourly 9 km Surface and Rootzone Soil Moisture Analysis Update (SPL4SMAU)

Major Version Science Version ID Maturity State Temporal Coverage Version Changes Date Implemented
Version 1
 
Vb1010 Beta (ReportPDF Icon) 2015-03-31 (01:30) to 2015-10-26 (01:30) First public data release 2015-10-30
Version 1
 
Vb1012 Beta (ReportPDF Icon) 2015-10-26 (01:30) to 2016-04-22 (01:30)

Input data source changed from SPL1CTB V1 Beta data to SPL1CTB V2 Validated-Stage 1 data.

2015-10-30
Version 2
 
Vv2010 Validated-Stage 2
(ReportPDF Icon)
2015-03-31 (01:30) to present Changes to this version include:
  • Transitioned to Validated-Stage 2
  • Using updated SPL1CTB V3 Validated data as input
  • Minor bug fixes
2016-04-21

SMAP L4 Global 3-hourly 9 km Surface and Rootzone Soil Moisture Geophysical Data (SPL4SMGP)

Major Version Science Version ID Maturity State Temporal Coverage Version Changes Date Implemented
Version 1
 
Vv1010 Beta (ReportPDF Icon) 2015-03-31 (00:00) to 2015-10-26 (00:00) First public data release 2015-10-30
Version 1
 
Vv1012 Beta (ReportPDF Icon) 2015-10-26 (00:00) to 2016-04-22 (00:00)

Input data source changed from SPL1CTB V1 Beta data to SPL1CTB V2 Validated-Stage 1 data.

2015-10-30
Version 2
 
Vv2010 Validated-Stage 2
(ReportPDF Icon)
2015-03-31 (00:00) to present Changes to this version include:
  • Transitioned to Validated-Stage 2
  • Using updated SPL1CTB V3 Validated data as input
  • Minor bug fixes
2016-04-21

SMAP L4 Global 9 km Surface and Rootzone Soil Moisture Land Model Constants (SPL4SMLM)

Major Version Science Version ID Maturity State Temporal Coverage Version Changes Date Implemented
Version 1
 
Vb1010 Beta (ReportPDF Icon) 2015-04-01 (00:00) to 2015-04-01 (23:59) First public data release 2015-10-30
Version 1
 
Vb1012 Beta (ReportPDF Icon) 2015-10-26 (00:00) to 2015-10-26 (23:59)

Input data source changed from SPL1CTB V1 Beta data to SPL1CTB V2 Validated-Stage 1 data.

2015-10-30
Version 2
 
Vv2010 Validated-Stage 2
(ReportPDF Icon)
2015-03-31 (00:00) to present Updated to coincide changes to SPL4SMAU V1 and SPL4SMGP V1.  2016-04-21

SMAP L4 Global Daily 9 km Carbon Net Ecosystem Exchange (SPL4CMDL)

Major Version Science Version ID Maturity State Temporal Coverage Version Changes Date Implemented
Version 1 Vb1010 Beta (ReportPDF Icon) 2015-04-13 (00:00) to 2016-04-21 (23:59) First public data release 2015-10-30
Version 2
 
Vv2010 Validated-Stage 2
(ReportPDF Icon)
2015-03-31 (00:00) to present

Changes to this version include:

  • Transitioned to Validated-Stage 2
  • Using SPL4SMAU V2 Validated and SPL4SMGP V2 Validated data as input
  • Update to process radiometer data from 2015-03-31 to 2015-04-12
  • Some data fields renamed from *_av to *_mean
  • Updated to have have continuous RMSE-based "quality" fields instead of the categorical quality flag in V1
2016-04-21

Naming Conventions

Major Version

Major versions indicate the Series- or Collection-level major version of SMAP data products. Major versions signify that one or more changes have been made that caused a scientific change in the data, including:

  • Change of input data used
  • Change to algorithm or processing software
  • Change to file-level metadata

Major version changes typically result in a reprocessing of the entire time series. As shown in Figure 1, the major version ID is located in SMAP HDF5 (.h5) data files within the DatasetIdentification group.

Figure 1. Major Versions of SMAP Data Products
To find the major version of a SMAP data product, navigate to DatasetIdentification within the Metadata group of any SMAP HDF5 (.h5) data file. The ECSVersionID = 004 indicates that these are Version 4 data.

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 major CRID 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 Major CRID Version Number
vvv 3-Digit Minor CRID 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

  • 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

Additionally, 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.

Temporal Coverage

Dates

All dates on this page are listed as four-digit year followed by two-digit month and two-digit day, such as 2015-12-31.

Times

Times are listed as two-digit hour followed by two-digit minute , such as 17:24. Times are in Coordinated Universal Time (UTC), which is also known as Greenwich Mean Time (GMT) and/or "Z" or "Zulu Time."