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AMSR-E/AMSR2 Unified Data - Versions
This page provides details of the processing and algorithm history for all versions of AMSR-E/AMSR2 Unified data products. For an explanation of version naming conventions such as product maturity codes and validation stages, refer to the Naming Conventions section of this page. For information about major instrument data loss periods, see the Instrument Data Loss Periods page (page content is forthcoming).
Naming Conventions
Identifying Version Numbers
Depending on the Order Data method you use, the version number will appear differently at the end of the product name.
If you order the data from Earthdata Search, the product name will be appended by a version number. The version is specified as a 3-digit alphanumeric code beginning with the letter 'V' (V001 indicates Version 1).
AMSR-E/AMSR2 Unified L2B Half-Orbit 25 km EASE-Grid Surface Soil Moisture V001.
If you order data from the Data Pool HTTPS directory, the version number is written at the end of the data set short name:
AU_Land.002.
Product Maturity Codes
AMSR-E/AMSR2 Unified data file/granule names include a product maturity code (such as B01, T02, or V03) to indicate which version of the algorithm was used to produce the data. The product maturity code includes both a maturity level (P, R, B, T, or V) and a two-digit iteration number, such as B02 in the following file name:
AMSR_U2_L2_Land_B02_201805292336_A.he5
All AMSR-E/AMSR2 Unified products are currently at the Beta (B) maturity level. Table 1 describes each product maturity level.
| Level | Description |
|---|---|
| P | Preliminary - refers to non-standard, near-real-time data available from NSIDC. These data are only available for a limited time until the corresponding standard product is ingested at NSIDC. |
| R | Near-Real-Time - refers to near-real-time data produced and distributed via the NASA Land Atmosphere Near-real-time Capability for EOS (LANCE) data system. |
| B | Beta - indicates a developing algorithm with updates anticipated. |
| T | Transitional - period between beta and validated where the product is past the beta stage, but not quite ready for validation. This is where the algorithm matures and stabilizes. |
| V | Validated - products are upgraded to Validated once the algorithm is verified by the algorithm team and validated by the validation teams. Validated products have an associated validation stage. Refer to Table 2 for a description of the stages. |
Validation Stage
Additionally, a stage (1, 2, or 3) may be appended to the product maturity code of Validated, such as V09-Stage3. Table 2 describes each validation stage.
| Validation Stage | Description |
|---|---|
| Stage1 | Product accuracy is estimated using a small number of independent measurements obtained from selected locations, time periods, and ground-truth/field program efforts. |
| Stage2 | Product accuracy is assessed over a widely distributed set of locations and time periods via several ground-truth and validation efforts. |
| Stage3 | 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. |
Data Products and Version Details
| Current Version: | Version 3 (V001) |
| Maturity Details: | B02 |
| Temporal Coverage: | 2012-07-02 (23:18) to present |
| Version Changes: | Since all sea ice products are produced by the same software (Delivery Algorithm Package), this version was generated as a result of reprocessing AU_SI25 to B02. There are no changes to this data in the B02 version. Only the file name has changed to reflect the new version. |
| B01 2012-07-02 to 2019-02-13 | Original at-launch version of data. |
|---|
AMSR-E/AMSR2 Unified L3 Daily 12.5 km Brightness Temperatures & Sea Ice Concentration Polar Grid (AU_SI12)
| Current Version: | Version 3 (V001) |
| Maturity Details: | B02 |
| Temporal Coverage: | 2012-07-02 (23:18) to present |
| Version Changes: | Since all sea ice products are produced by the same software (Delivery Algorithm Package), this version was generated as a result of reprocessing AU_SI25 to B02. There are no changes to this data in the B02 version. Only the file name has changed to reflect the new version. |
| B01 2012-07-02 to 2019-02-13 | Original at-launch version of data. |
|---|
AMSR-E/AMSR2 Unified L3 Daily 25 km Brightness Temperatures & Sea Ice Concentration Polar Grid (AU_SI25)
| Current Version: | Version 3 (V001) |
| Maturity Details: | B02 |
| Temporal Coverage: | 2012-07-02 (23:18) to present |
| Version Changes: | The B02 update corrects an issue with the parameter designation (indexing) of some brightness temperature values in the B01 product. |
| B01 2012-07-02 to 2019-02-13 | Original at-launch version of data. |
|---|
| Current Version: | Version 3 (V001) |
| Maturity Details: | B02 |
| Temporal Coverage: | 2012-07-02 (23:18) to present |
| Version Changes: | The B02 update corrects an error that caused only half of each swath to be processed. |
| B01 2012-07-02 to 2019-02-13 | Original at-launch version of data. |
|---|
