AMSR-E Data Versions

This page provides details of the processing and algorithm history for all versions of AMSR-E data products. For information about major instrument data loss periods, see the Instrument Data Loss Periods document in the Documentation tab.

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, for example, the version number (V002 in this case) is written at the end of the data set title:

AMSR-E/AQUA MONTHLY L3 GLOBAL SNOW WATER EQUIVALENT EASE-GRIDS V002.

If you order data from the Data Pool HTTPS directory, the version number is written at the end of the data set short name: AE_MoSno.002.

Product Maturity Codes

AMSR-E data file 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 B06 in the following example file name: AMSR_E_L3_SeaIce25km_B06_20080207.hdf.

Description of Product Maturity Levels

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.

Description of Validation Stages

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

AMSR-E/Aqua L1A Raw Observation Counts (AMSREL1A)

Current Version: Version 3 (V003)

Maturity Details: N/A

Temporal Coverage: 2002-06-01 (17:24) to 2011-10-04 (06:03)

Version Changes

The improved V003 AMSREL1A product features empirical corrections to the co-registration parameters A1 and A2, and an updated parameter file used for correcting the AMSR-E 89 GHz position information. As a result, Version 3 AMSREL1A data provide improved accuracy for the following: Latitude and Longitude, land/ocean flags, earth incidence angle, earth azimuth angle, sun azimuth angle, and sun elevation angle. Additionally, the HDF-EOS version was updated from 4.2r1 to 4.2r4.

Version 2 Processing and Algorithm History

Temporal Coverage: 2002-06-19 (06:15) to 2011-09-27 (05:57)

The V002 AMSREL1A product features empirical corrections to the Aqua scan azimuth and satellite flight direction. With corrected sun azimuth, sun elevation, earth azimuth, and earth incidence angles, the geometric accuracy of AMSR-E 89 GHz data improved to within 2 km, compared to Version 1 AMSREL1A data.

Version 1 Processing and Algorithm History

Temporal Coverage: 2002-06-22 (00:11) to 2005-03-01 (00:14)

Original at-launch version of data.

AMSR-E/Aqua L2A Global Swath Spatially-Resampled Brightness Temperatures (AE_L2A)

Current Version: Version 4 (V004)

Maturity Details: V13-Stage 3

Temporal Coverage: 2002-06-01 (00:11) to 2011-10-04 (06:03)

Version Changes

  • Complete recalibration to RSS Version 8 standard, as follows:
  • Intercalibrated with other microwave radiometers, especially GMI[1], WindSat, and TMI[2]
  • Calibrated with improved Ocean Radiative Transfer Model (ORTM)
  • Updated ocean emissivity model (Meissner and Wentz 2012)
  • Improved calibration over warm scenes (land and cryosphere), based on heavily vegetated tropical rainforest scenes
  • Adjusted Antenna Pattern Coefficients (APC) for cross-polarization and spillover
  • The 18.7 GHz center observation frequency has been shifted back to nominal
  • Rederived algorithm to compute the AMSR-E effective hot load temperature based on 1 hour colocations with TMI

Version 3 Processing and Algorithm History

V12-Stage3: Temporal Coverage: 2011-01-26 (09:40) to 2011-10-03 (21:49)

  • Complete recalibration to RSS Version 7 standard, as follows:
  • Intercalibration with other microwave radiometers, particularly SSM/I F13 and WindSat
  • Calibration with improved Radiative Transfer Model (RTM): RSS RTM Version 2011
  • Updated ocean emissivity model (Meissner and Wentz 2012)
  • Adjustment of the water vapor and oxygen absorptions, particularly the water vapor continuum absorption
  • Improved calibration over land, based on heavily vegetated tropical rainforest scenes
  • Nonlinearity correction at 18.7 GHz, brightness temperatures approx. 2°K lower over land
  • Adjustment to Antenna Pattern Coefficients (APC) for cross-polarization and spillover
  • Slight shift to the 18.7 GHz center observation frequency
  • Adjustment of effective hot-load temperature
  • Improved Radio Frequency Interference (RFI) flagging in response to new geostationary sources

Version 2 Processing and Algorithm History

V11-Stage3: Temporal coverage: 2011-01-26 (09:40) to 2011-10-03 (21:49)

  • Updated the product maturity code to include R, for near-real-time data. There were no changes to the science algorithm in this version.

V10-Stage3: 2002-06-19 (00:29) to 2011-01-26 (09:41)

  • Computed a checksum from the latitudes, longitudes, and brightness temperatures. Attached it to the L2A file as a global attribute, and reported it in the QA file.
  • RSS added the glint angles of the DirecTV 10 and 11 satellites to the Geostationary_Satellite_Glint_Angles field. The low glint angles correlate well with the recent observed RFI artifacts. Over oceans, RFI can be intense: +50 K for 18.7V, and +100 K for 18.7H. Cases this large correspond to low wind conditions with very smooth seas. Initial analysis over land did not reveal significant RFI impacts. The affected period for this RFI is from July 2007 forward.

V09-Stage3: Temporal coverage: 2002-06-19 (00:29) to 2009-04-16 (04:11)

  • This version corrects the errors in the resampled 89.0 GHz Horizontal data fields (89.0H_Res.#_TB) which were discovered in March 2008. Only V08 files from 19 June 2002 00:29 through 4 November 2004 05:43 contained the bad data. For more information, please see the AMSR-E L2A Brightness Temperatures: Bad Resampled 89 GHz Horizontal Data news brief on the AMSR-E News page.

V08-Stage3: Temporal coverage: 2002-06-19 (23:40) to 2008-03-07 (00:30)

  • This validated version of the algorithm includes updated global attributes and inventory metadata to reflect a version change from B07 to V08. There were no changes to the science algorithm from B07 to V08.

Version 1 Processing and Algorithm History

B07: Temporal coverage: 2006-03-21 (04:16) to 2006-08-01 (00:29)

The purpose of this algorithm was to:

  • Correct the earth incidence angle calculation to correct for instrument roll.
  • Modify along-scan antenna temperature adjustment using the new roll angle.
  • Correct geolocation errors.
  • Update the resampling weights of the 6.9 and 10.6 GHz channels.
  • Recalibrate the hot load and revise the method for computing the effective hot load temperature.
  • Introduce a flagging algorithm for RFI from European Geostationary TV satellites.
  • Correct for the August-September 2003 Aqua pitch error.
  • Correct for lunar radiation entering the cold mirror.
  • Match the 89A and 89B observations when doing resampling.
  • Use UT1 time to compute Earth rotation angle for geolocation accuracy and to avoid discontinuity in the geolocations parameters when a leap second occurs.
  • Assign units, scale factor, and offset to all data fields.
  • Modify swath attributes and data arrays.

B06: Temporal coverage: 2005-09-28 (05:41) to 2006-03-21 (04:16)

  • Corrected rounding error in the RangeEndingTime swath attribute and metadata item.

B05: Temporal coverage: 2002-06-19 (06:15) to 2011-09-27 (05:57)

  • Changes to this algorithm include:
  • Improved geolocation.
  • Increased Earth Incidence angle to two bytes.
  • Augmented the Scan_Quality_Flag with a spin rate flag and a flag indicating when observations are not all on the Earth.

B04: Temporal coverage: 2005-03-01 (00:14) to 2005-08-15 (10:13)

Changes to this algorithm include:

  • The name of the unsampled elements changed from Level1B to not-resampled.
  • Degree units are more consistent, for example, deg rather than deg. for both angle and temperature.
  • Level-2A metadata include CoRegistrationParameterA1 and CoRegistrationParameterA2 fields.
  • Position_in_Orbit was written as an 8-byte number rather than 4-byte.
  • Data include new fields for geostationary satellite glint and effective cold target temperature.
  • The ProcessingVersionNumber swath attribute was eliminated.

B03: Temporal coverage:  2005-01-02 (00:27) to 2005-03-01 (00:14)

  • Offers improved calibration because the coefficients no longer depend on SSM/I or TMI. Data are also closer to real time. AE_L2A continues to derive data from the AMSR-E 89 GHz-B feedhorn because of problems with the 89 GHz-A feedhorn.

B02: Temporal coverage: 2004-11-04 (00:46) to 2005-01-02 (00:27)

  • Corrects problems with the AMSR-E 89 GHz A-feedhorn by producing data from the 89 GHz B-feedhorn only.

B01: Temporal coverage: 2002-06-18 (23:40) to 2004-11-04 (00:46)

  • Original at-launch version of data.

AMSR-E/Aqua L2B Surface Soil Moisture, Ancillary Parms, & QC EASE-Grids (AE_Land)

Current Version: Version 3 (V003)

Maturity Details: V11-Stage 1

Temporal Coverage: 2010-10-19 (23:59) to 2011-10-4 (06:51)

Version Changes

  • Soil moisture is now estimated using two different approaches - the Normalized Polarization Difference algorithm (NPD) and the Single Channel Algorithm (SCA) - to be consistent with the AU_Land soil moisture product. As a result, output parameters are now the same as AU_Land.
  • File format changed to HDF-EOS5.

Version 2 Processing and Algorithm History

V10-Stage 1: Temporal Coverage: 2002-06-01 (11:22) to 2011-10-3 (21:49)

  • Updated the product maturity code to include R, for near-real-time data. There were no changes to the science algorithm in this version.

V09-Stage1: Temporal coverage: 2002-06-19 (00:29) to 2010-10-20 (00:00)

  • Updated the product maturity code status to Validated. There were no changes to the science algorithm in this version.

T08: Temporal coverage: 2004-07-03 (16:50) to 2008-12-05 (02:55)

  • Changed the processing code to produce only a QA file when there is no L2A brightness temperature data qualified for retrieval. There were no changes to the science algorithm in this version. Only being used for reprocessing. T06 is still being used in forward processing.

T07: Temporal coverage: 2002-06-19 (00:29) to 2004-07-03 (16:51)

  • Converted the algorithm code to run on Linux. There were no changes to the science algorithm in this version.

T06: Temporal coverage: 2007-04-19 (21:24) to 2008-07-06 (00:24)

  • Updated the product maturity code status to Transitional (T). There are no algorithm changes from version B05 to T06.

Version 1 Processing and Algorithm History

B05: Temporal coverage: 2006-03-10 (09:31) to 2007-04-19 (21:25)

  • Updates to accommodate the L2A version B07 format changes.

B04: Temporal coverage: 2002-06-18 (23:40) to 2006-03-10 (09:31)

  • Update L2A reader for version 5 L2A.

B03: Temporal coverage: 2005-06-02 (23:37) to 2005-08-25 (00:57)

  • Minor modification to the soil moisture QC within the science code.

B02: Temporal coverage: 2005-02-09 (22:04) to 2005-06-29 (04:21)

Changes to this algorithm include:

  • The number of pixels per scan changed from 196 to 243 (the full swath width).
  • Updated land and surface type classification parameters and regression parameters.
  • Updated brightness temperature quality assessment to prevent out-of-bounds brightness temperatures from being gridded.
  • A new frozen ground classification.
  • Using the difference of the 10.6V GHz and 18.0V GHz as the only criteria for defining Radio Frequency Interference (RFI). If the difference is greater than or equal to 5.0, the pixel is flagged as contaminated with RFI.
  • Upgrades to the surface type classification to indicate combinations of surface types.

B01: Temporal coverage: 2002-06-18 (23:40) to 2005-02-09 (22:05)

  • Original at-launch version of data.

AMSR-E/Aqua Daily L3 Surface Soil Moisture, Interpretive Parameters, & QC EASE-Grids (AE_Land3)

Current Version: Version 2 (V002)

Maturity Details: V07-Stage 1

Temporal Coverage: 2010-08-27 (00:36) to 2011-10-3 (21:49)

Version Changes

Updated the product maturity code to include R, for near-real-time data. There were no changes to the science algorithm in this version.

Version 2 Processing and Algorithm History

V06-Stage1: Temporal coverage: 2002-06-19 (00:29) to 2010-08-27 (00:37)

  • Updated the product maturity code status to Validated. There were no changes to the science algorithm in this version.

T05: Temporal coverage: 2002-06-19 (00:29) to 2008-12-01 (00:02)

Changes included in this version are:

  • Updated the product maturity code status to Transitional (T). There are no algorithm changes from version B04 to T05.
  • Converted the algorithm code to run on Linux. This version is not compatible with SGI IRIX.

Version 1 Processing and Algorithm History

B04: Temporal coverage: 2007-04-19 (00:42) to 2008-07-06 (00:24)

  • Accommodates L2 Land transitional file input.

B03: Temporal coverage: 2002-06-18 (23:40) to 2007-04-19 (12:49)

  • Corrects structural metadata error, introduced in B02, in which the corner coordinates were incorrectly expressed in degrees. This caused any geolocation function or software that used the HDF-EOS library, including spatial subsetting via the NASA Warehouse Inventory Search Tool (WIST), to return erroneous results. In B03, the corner coordinates are properly expressed in meters.

B02: Temporal coverage: 2005-02-15 to 2005-09-05

  • Input Level-2B product uses full swath (243 pixels). Combines Surface Type and Inversion QC Flag 1 from the Level-2B product to form the Inversion QC Flag field.

B01: Temporal coverage: 2002-06-18 to 2005-02-22

  • Original at-launch version of data.

AMSR-E/Aqua L2B Global Swath Ocean Products derived from Wentz Algorithm (AE_Ocean)

Current Version: Version 2 (V002)

Maturity Details: V07-Stage 2

Temporal Coverage: 2010-10-19 (23:59) to 2011-10-3 (21:49)

Version Changes

Updated the product maturity code to include R, for near-real-time data. There were no changes to the science algorithm in this version.

Version 2 Processing and Algorithm History

V06-Stage2: Temporal coverage: 2002-06-19 (00:29) to 2010-10-20 (00:00)

  • Converted the algorithm code to run on Linux. There were no changes to the science algorithm in this version.

V05-Stage2: Temporal coverage: 2007-05-09 (02:52) to 2008-07-06 (00:24)

  • Changes included in this version are:
  • Updated global attributes and inventory metadata to reflect product maturity change from Beta to Validated.
  • Improved beamfilling correction to account for different footprint sizes of different frequencies.
  • A new expression for the rain column height that yields more accurate rain flags is the third byte of the Ocean_products_quality_flag, which identify the proximity and intensity of rain. This is useful for quality assessment of SST and wind speed. The meanings of the rain flags have not changed.

Version 1 Processing and Algorithm History

B04: Temporal coverage: 2006-03-10 (09:31) to 2007-05-09 (02:52)

  • Updates to accommodate the L2A version B07 format changes.

B03: Temporal coverage: 2002-06-18 (23:40) to 2006-03-10 (09:31)

Changes to this algorithm include:

  • A salinity correction.
  • A more sophisticated post hoc correction for anomalies.
  • RFI identification and flagging.
  • An update to the L2A reader to accommodate version 5 L2A format.
  • Use of full swath.
  • A new flag added to the ocean_products_quality_flag array to identify geostationary satellite RFI.
  • Detection of sea ice using the NASA Team Sea Ice Algorithm.
  • The redefinition of default values in arrays to eliminate ambiguity.
  • The addition of units for all fields.
  • Updates to the quality flags.

B02: Temporal coverage: 2005-02-07 (23:56) to 2005-08-23 (04:27)

  • Updated the L2A reader in preparation for version B04 L2A.

B01: Temporal coverage: 2002-06-18 (23:40) to 2005-02-07 (23:56)

  • Original at-launch version of data.

AMSR-E/Aqua Daily L3 Global Ascending/Descending .25x.25 deg Ocean Grids (AE_DyOcn)

Current Version: Version 2 (V002)

Maturity Details: V05-Stage 2

Temporal Coverage: 2010-08-27 (00:36) to 2011-10-3 (21:49)

Version Changes

Updated the product maturity code to include R, for near-real-time data. There were no changes to the science algorithm in this version.

Version 2 Processing and Algorithm History

V04-Stage2: Temporal coverage: 2002-06-19 (00:29) to 2010-08-27 (00:37)

  • Changes to the science algorithm for this version include:
  • Added radio frequency interference (RFI) filter for DirectTV, based on RFI angles below 30 degrees and within approximately 350 km of the U.S. coast.
  • Added an RFI filter for the Atlantic Bird 4 satellite in the Mediterranean Sea, based on the difference between the Sea Surface Temperature (SST) and WIND product at different resolutions.
  • Updated the RFI filter for the Hotbird/Astra to account for increasing extent of broadcasts; three geographic regions filter RFI angles up to 15, 22 and 27 degrees.
  • Added an RFI filter for the Ascension Island, based on the difference between low and very low-resolution SSTs.
  • Added an RFI filter in the Gulf of Aden, based on the difference between SST and WIND products at different resolutions.
  • Added a filter to remove all data over the shrinking Aral Sea due to land contamination.
  • Added an RFI angle grid as a parameter.

V03-Stage2: Temporal coverage: 2002-06-19 (00:29) to 2010-04-29 (00:38)

  • Changes included in this version are:
    • Updated the product maturity code status to Validated (V). There are no algorithm changes from version B02 to V03.
    • Converted the algorithm code to run on Linux. This version is not compatible with SGI IRIX.

Version 1 Processing and Algorithm History

B02: Temporal coverage: 2005-08-19 (12:44) to 2008-07-06 (00:24)

  • This algorithm uses full swath, which includes the addition of units for all parameters and excludes observations that meet any of the following conditions:

The TB ice flag and the climate ice flag indicate the presence of ice.

  • Contamination by sun glint or RFI.
  • L2B ocean parameter(s) out of bounds.
  • Suspect L2B ocean quality flags.

B01: Temporal coverage: 2002-06-18 (23:40) to 2005-08-19 (12:44)

  • Original at-launch version of data.

AMSR-E/Aqua Weekly L3 Global Ascending/Descending .25x.25 deg Ocean Grids (AE_WkOcn)

Current Version: Version 2 (V002)

Maturity Details: V05-Stage 2

Temporal Coverage: 2010-08-22 (00:18) to 2011-10-2 (00:30)

Version Changes

Updated the product maturity code to include R, for near-real-time data. There were no changes to the science algorithm in this version.

Version 2 Processing and Algorithm History

V04-Stage2: Temporal coverage: 2002-06-19 (00:29) to 2010-08-22 (00:18)

  • Changes to the science algorithm for this version include:
  • Added radio frequency interference (RFI) filter for DirectTV, based on RFI angles below 30 degrees and within approximately 350 km of the U.S. coast.
  • Added an RFI filter for the Atlantic Bird 4 satellite in the Mediterranean Sea, based on the difference between the Sea Surface Temperature (SST) and WIND product at different resolutions.
  • Updated the RFI filter for the Hotbird/Astra to account for increasing extent of broadcasts; three geographic regions filter RFI angles up to 15, 22 and 27 degrees.
  • Added an RFI filter for the Ascension Island, based on the difference between low and very low-resolution SSTs.
  • Added an RFI filter in the Gulf of Aden, based on the difference between SST and WIND products at different resolutions.
  • Added a filter to remove all data over the shrinking Aral Sea due to land contamination.
  • Added an RFI angle grid as a parameter.

V03-Stage2: Temporal coverage: 2002-06-19 (00:29) to 2010-04-25 (00:13)

Changes included in this version are:

  • Updated the product maturity code status to Validated (V). There are no algorithm changes from version B02 to V03.
  • Converted the algorithm code to run on Linux. This version is not compatible with SGI IRIX.

Version 1 Processing and Algorithm History

B02: Temporal coverage: 2005-08-14 (12:26) to 2008-07-06 (00:24)

  • This algorithm uses full swath, which includes the addition of units for all parameters and excludes observations that meet any of the following conditions:
  • The TB ice flag and the climate ice flag indicate the presence of ice.
  • Contamination by sun glint or RFI.
  • L2B ocean parameter(s) out of bounds.
  • Suspect L2B ocean quality flags.

B01: Temporal coverage: 2002-06-18 (23:40) to 2005-08-14 (12:26)

  • Original at-launch version of data.

AMSR-E/Aqua Monthly L3 Global Ascending/Descending .25x.25 deg Ocean Grids (AE_MoOcn)

Current Version: Version 2 (V002)

Maturity Details: V05-Stage 2

Temporal Coverage: 2010-08-01 (00:49) to 2011-10-1 (00:36)

Version Changes

Updated the product maturity code to include R, for near-real-time data. There were no changes to the science algorithm in this version.

Version 2 Processing and Algorithm History

V04-Stage2: Temporal coverage: 2002-06-19 (00:29) to 2010-08-01 (00:49)

Changes to the science algorithm for this version include:

  • Added radio frequency interference (RFI) filter for DirectTV, based on RFI angles below 30 degrees and within approximately 350 km of the U.S. coast.
  • Added an RFI filter for the Atlantic Bird 4 satellite in the Mediterranean Sea, based on the difference between the Sea Surface Temperature (SST) and WIND product at different resolutions.
  • Updated the RFI filter for the Hotbird/Astra to account for increasing extent of broadcasts; three geographic regions filter RFI angles up to 15, 22 and 27 degrees.
  • Added an RFI filter for the Ascension Island, based on the difference between low and very low-resolution SSTs.
  • Added an RFI filter in the Gulf of Aden, based on the difference between SST and WIND products at different resolutions.
  • Added a filter to remove all data over the shrinking Aral Sea due to land contamination.
  • Added an RFI angle grid as a parameter.

V03-Stage2: Temporal coverage: 2002-06-19 (00:29) to 2010-04-01 (00:00)

Changes included in this version are:

  • Updated the product maturity code status to Validated (V). There are no algorithm changes from version B02 to V03.
  • Converted the algorithm code to run on Linux. This version is not compatible with SGI IRIX.

Version 1 Processing and Algorithm History

B02: Temporal coverage: 2005-08-23 to 2008-07-06 (00:24)

  • This algorithm uses full swath, which includes the addition of units for all parameters and excludes observations that meet any of the following conditions:
  • The TB ice flag and the climate ice flag indicate the presence of ice.
  • Contamination by sun glint or RFI.
  • L2B ocean parameter(s) out of bounds.
  • Suspect L2B ocean quality flags.

B01: Temporal coverage: 2002-06-18 to 2005-08-23

  • Original at-launch version of data.

AMSR-E/Aqua L2B Global Swath Surface Precipitation GSFC Profiling Algorithm (AE_Rain)

Current Version: Version 3 (V003)

Maturity Details: V12-Stage 2

Temporal Coverage: 2002-06-01 (00:11) to 2011-10-4 (06:03)

Version Changes

Changes were implemented on 11 November 2015. Version 3 utilizes the GPROF 2010 Version 2 algorithm and Version 3 Level-2A Brightness Temperatures as input. Version 3 now includes both rain and solid precipitation rates and types, as well as ISO lineage metadata.

Version 2 Processing and Algorithm History

V11-Stage 2: Temporal coverage: 2010-10-19 (23:59) to 2011-10-3 (21:49)

  • Updated the product maturity code to include R, for near-real-time data. There were no changes to the science algorithm in this version.

V10-Stage2: Temporal coverage: 2002-06-19 (00:29) to 2010-10-20 (00:00)

  • Converted the algorithm code to run on Linux. There were no changes to the science algorithm in this version.

V09-Stage2: Temporal coverage: 2006-11-13 (02:58) to 2008-07-06 (00:24)

  • This validated version of the algorithm includes updated global attributes and inventory metadata to reflect a version change from B08 to V09. There were no changes to the science algorithm from B08 to V09.

Version 1 Processing and Algorithm History

B08: Temporal coverage: 2006-03-10 (09:31) to 2006-11-13 (02:58)

  • Updates to accommodate the L2A version B07 format changes.

B07: Temporal coverage: 2005-08-23 (04:27) to 2006-03-10 (09:31)

  • Update L2A reader for version 5 L2A.

B06: Temporal coverage: 2005-06-02 (04:28) to 2005-08-23 (04:27)

  • Rain rate is now calculated for surface types of "possible ice over coast."

B05: Temporal coverage: 2005-04-01 (04:27) to 2005-07-06 (04:28)

  • Improves low coastal rain rates.

B04: 2004-11-04 (00:46) to 2005-04-01 (04:28)

  • Corrects errors resulting from the AMSR-E 89 GHz-A feedhorn failure. The number of pixels per scan changed from 468 to 392.

B03: Temporal coverage: 2004-09-24 (14:04) to 2004-11-04 (00:46)

  • Corrects low tropical coastal rainfall retrievals and modifies calculations of cold season coastal rainfall estimates to eliminate false rain signatures, which also eliminates most true rainfall signatures for this condition. The algorithm also eliminates rainfall retrievals over ocean when the sun glint is greater than 20 degrees.

B02: Temporal coverage: 2002-06-18 (23:40) to 2004-09-24 (14:04)

  • First public version of data. The number of pixels per scan changed from 392 to 486 (the full swath width).

B01: Original at-launch version of data.

AMSR-E/Aqua Monthly L3 5x5 deg Rainfall Accumulations (AE_RnGd)

Current Version: Version 2 (V002)

Maturity Details: V07-Stage 2

Temporal Coverage: 2011-01-01 (00:42) to 2011-10-1 (00:36)

Version Changes

Updates to this version resolved a date range issue which halted production beginning in January 2011.

Version 2 Processing and Algorithm History

V06-Stage2: Temporal coverage: 2002-06-19 (00:29) to 2011-01-01 (00:42)

Changes included in this version are:

  • Updated the product maturity code status to Validated (V).
  • Skipped duplicate (overlapping) scans in consecutive L2A files.
  • Improved L2A brightness temperature binning for monthly ocean grids.
  • Updated the leap second ancillary file to include the leap second which occurred at the end of 2005.
  • Converted the algorithm code to run on Linux. This version is not compatible with SGI IRIX.
  • Added a shell script that is used during installation.
  • Set the default system stacksize parameter to unlimited.

Version 1 Processing and Algorithm History

B05: Temporal coverage: 2006-03-01 (00:33) to 2008-07-06 (00:24)

  • Updates to accommodate the L2A version B07 format changes.

B04: Temporal coverage:  2005-08-25 to 2006-03-01 (00:33)

  • Updates to L2A reader for version B05 L2A.

B03: Temporal coverage: 2004-11-01 to 2005-08-25

  • Corrects low tropical coastal rainfall retrievals and modifies calculations of cold season coastal rainfall estimates to eliminate false rain signatures, which also eliminates most true rainfall signatures for this condition. The algorithm also eliminates rainfall retrievals over ocean when the sun glint is greater than 20 degrees. In only AE_RnGd, the B03 algorithm lowers the upper limit for acceptable brightness temperatures over ocean and corrects minor errors in the processing code.

B02: Temporal coverage: 2002-06-18 to 2004-11-01

  • First public version of data. Modified the L2B Rain rate product reader so that the full swath width of the L2B product can be used. Updated to prevent any missing data from being counted in the L2B histogram

B01: Original at-launch version of data.

AMSR-E/Aqua Daily L3 6.25 km 89 GHz Brightness Temperature Polar Grids (AE_SI6)

Current Version: Version 3 (V003)

Maturity Details: V15-Stage 1

Temporal Coverage: 2002-06-01 (17:24) to 2011-10-04 (06:51)

Version Changes

Changes to the Version 3 algorithm for these data include:

  • Use of the most recent version (Version 3) of the AMSR-E/Aqua L2A Global Swath Spatially-Resampled Brightness Temperatures data as input
  • An improved Antarctic land mask: Includes an updated ice shelf definition created by the National Ice Center Science Department in June 2011, and an updated shoreline developed from ENVISAT and RADARSAT imagery from October 2009 to April 2010. Also, this updated version no longer uses the Level-2A land flag and only uses the updated land mask for surface type classification in the southern hemisphere sea ice concentration algorithm.
  • Inclusion of ISO lineage metadata

Version 2 Processing and Algorithm History

V14-Stage1: Temporal coverage: 2010-08-27 (00:36) to 2011-10-03 (21:49)

  • A new maturity level was implemented to coincide with updates to other AMSR-E sea ice products. There were no changes to the science algorithm for this product from V13-Stage1 to V14-Stage1. The only change was to the file name.

V13-Stage1: Temporal coverage: 2010-08-27 (00:36) to 2011-10-03 (21:49)

Changes included in this version are:

  • Updated the product maturity code to include R, for near-real-time data.
  • Corrected an error in the V12 code which produced the out-of-range value of -310 in the sea ice concentration difference field when data from the Bootstrap Basic Algorithm (BBA) were missing.

V12-Stage1: Temporal coverage: 2002-06-19 (00:29) to 2010-08-27 (00:37)

  • Corrected an error in the method for applying the multi-year sea ice mask that had caused large areas of Arctic to be erroneously masked in the Snow Depth on Sea Ice parameter. The multi-year sea ice mask and the snow melt mask are now stored within the AMSR-E/Aqua Daily L3 12.5 km Brightness Temperature, Sea Ice Concentration, & Snow Depth Polar Grids (AE_SI12) product. The AE_SI12 product is the only sea ice product with the Snow Depth on Sea Ice parameter, but all AMSR-E sea ice products use the same production code and therefore will be processed with the V12 algorithm.

V11-Stage1: Temporal coverage: 2002-06-19 (00:40) to 2010-04-24 (00:13)

  • Corrected an error in the snow depth over sea ice retrieval in the Southern Hemisphere. This error, introduced in V10, caused snow depth to be overestimated by a factor of about two. AE_SI12 is the only product with the Snow Depth on Sea Ice parameter, but all AMSR-E sea ice products use the same production code and will be processed with the V11 algorithm.

V10-Stage1: Temporal coverage: 2002-06-19 (00:29) to 2009-05-28 (00:41)

  • Modified the tie point tables for the Antarctic.

V09: 2008-09-21 Temporal coverage: (00:44) to 2009-01-26 (00:03)

  • A new sea ice version was implemented to validate sea ice. There were no changes to the science algorithm from T08 to V09.The only change was to the file name.

T08: Temporal coverage: 2002-06-19 (00:29) to 2008-09-21 (00:44)

  • The AMSR-E sea ice temperature grids were removed from the 25 km product because of inherent ambiguities between changes in the physical temperature of the ice and changes in the ice emissivity. Instead, the panel suggested that an AMSR-E sea ice drift product be developed. Also, this algorithm includes all modifications made in version T07.

T07: Data never produced using this algorithm version. Algorithm updates included the following:

  • Updated the product maturity code status to Transitional (T).
  • Updated the sea ice concentration parameters.
  • Converted the algorithm code to run on Linux. This version is not compatible with SGI IRIX.
  • Set the default system stacksize parameter to unlimited.
  • Added a shell script that is used during installation.
  • Added new flag values for the 12.5 km snow depth product such as:
  • 140 indicates multiyear sea ice
  • 150 indicates variability in snow depth
  • 160 indicates snow melt.

Version 1 Processing and Algorithm History

B06: Temporal coverage: 2006-03-16 (00:39) to 2008-07-06 (00:24)

  • Updates to accommodate the L2A version B07 format changes.

B05: Temporal coverage: 2005-09-05 (00:38) to 2006-03-16 (00:40)

This algorithm includes:

  • Incorporation of the TLSCF L2A B05 reader.
  • Calculation of Southern Hemisphere parameters based on the NASA Team 2 algorithm instead of the Bootstrap algorithm.
  • Modification of difference arrays in Southern Hemisphere; all difference arrays now reflect the difference in the Bootstrap algorithm from the stored NASA Team 2 algorithm.
  • Updates to error reporting.
  • Updates for local only Global Hydrology and Climate Center Science Investigator-led Processing System (GHCC-SIPS) HDF-EOS version 2.13 grid API (GDapi.c) to store the eccentricity squared projection parameter to 9 decimal places in the structural metadata.

B04: Temporal coverage: 2005-02-25 (00:39) to 2005-09-05 (00:38)

  • This algorithm adapts to the B04 L2A format changes.

B03: Temporal coverage: 2004-09-24 (00:03) to 2005-02-25 (00:39)

The following B03 algorithm changes apply only to data derived from the Bootstrap sea ice algorithm:

  • Uses the 37H GHz channel in the sea ice concentration algorithm.
  • Updates emissivity values.
  • Significantly updates the bootstrap sea ice concentration algorithm.
  • Adds brightness temperatures to threshold checks.
  • Modifies the brightness temperature upper limit value from 350 K to 320 K.
  • Also, a known issue exists in this version. In the HDF-EOS structural metadata, the eccentricity squared projection parameter is rounded to only four significant digits, whereas the program actually uses a value with seven significant digits (0.006694 vs. 0.006693883).

B02: Temporal coverage: 2002-06-18 (23:40) to 2004-09-24 (00:03)

  • First public version of data. The following B02 algorithm changes apply only to data derived from the Bootstrap sea ice algorithm:
  • Uses the full swath.
  • Updates emissivity values based on date.
  • Updates intercept parameters used in line-fitting routines.
  • Adds 37H GHz to the argument list for Southern Hemisphere routines.
  • Eliminates overlapping scans between passes.
  • Updates weather filter parameters.
  • Updates brightness temperature tie points for ice concentration.

B01: Original at-launch version of data.

AMSR-E/Aqua Daily L3 Global Snow Water Equivalent EASE-Grids (AE_DySno)

Current Version: Version 2 (V002)

Maturity Details: V10-Stage 1

Temporal Coverage: 2010-08-27 (01:26) to 2011-10-3 (21:49)

Version Changes

Updated the product maturity code to include R, for near-real-time data. There were no changes to the science algorithm in this version.

Version 2 Processing and Algorithm History

V09-Stage1: Temporal coverage: 2002-06-19 (00:29) to 2010-08-27 (00:37)

  • Changes included in this version are:
  • Updated the product maturity code status to Validated. There are no algorithm changes from T08 to V09.
  • Corrected file start/end times in the metadata to accurately reflect only descending orbits.
  • Removed version numbers from ancillary file names.
  • Updated the ancillary file Combined_SnowImp_and_LOCI_mask_EASE_Both.

T08: Temporal coverage: 2002-06-19 (00:29) to 2008-12-01 (00:02)

Changes included in this version are:

  • Updated the product maturity code status to Transitional (T). There are no algorithm changes from version B07 to T08.
  • Converted the algorithm code to run on Linux. This version is not compatible with SGI IRIX.
  • Improved input list error checking.
  • Set the default system stacksize parameter to unlimited.

Version 1 Processing and Algorithm History

B07: Temporal coverage: 2006-03-31 (00:46) to 2008-07-06 (00:24)

  • Added the scale factor attribute to Snow Water Equivalent arrays.

B06: Temporal coverage: 2006-03-16 (00:39) to 2006-03-31 (00:46)

  • Updates to accommodate the L2A version B07 format changes.

B05: Temporal coverage: 2006-01-14 (12:20) to 2006-03-16 (00:40)

This algorithm includes:

  • Updates to the forest cover ancillary files. Two MODIS products are now used to help correct for forest attenuation.
  • The daily product retrievals are now performed on the AMSR-E individual Tb samples, which are then averaged to the EASE-Grid 25x25 km Northern and Southern Hemisphere projection grid.
  • Retrievals are calibrated for snow depth with a snow density climatology file used to convert snow depth to Snow Water Equivalent (SWE).

B04: Temporal coverage: 2005-02-25 (00:39) to 2006-01-14 (12:20)

  • This algorithm adapts to the B04 L2A format changes.

B03: Temporal coverage: 2004-11-25 (12:15) to 2005-02-25 (00:39)

This algorithm:

  • Contains ancillary file updates.
  • Uses satellite attitude information.
  • Adds brightness temperature limit checks.
  • Eliminates checks for rain, cold rain, and wet snow.
  • Eliminates explicit definition of xdim and ydim in the grid setup.

B02: Temporal coverage: 2002-06-19 (00:29) to 2004-11-28 (00:46)

Changes to this algorithm include:

  • The number of pixels per scan changed from 196 to 243 (the full swath width).
  • Updated land and surface type classification parameters and regression parameters.
  • Updated brightness temperature quality assessment to prevent out-of-bounds brightness temperatures from being gridded.
  • A new frozen ground classification.
  • Using the difference of the 10.6V GHz and 18.0V GHz as the only criteria for defining Radio Frequency Interference (RFI). If the difference is greater than or equal to 5.0, the pixel is flagged as contaminated with RFI.
  • Upgrades to the surface type classification to indicate combinations of surface types.

B01: Original at-launch version of data.

AMSR-E/Aqua Daily L3 12.5 km Brightness Temperature, Sea Ice Concentration, & Snow Depth Polar Grids (AE_SI12)

Current Version: Version 3 (V003)

Maturity Details: V15-Stage 1

Temporal Coverage: 2002-06-01 (00:29) to 2011-10-04 (06:51)

Version Changes

Changes to the Version 3 algorithm for these data include:

  • Use of the most recent version (Version 3) of the AMSR-E/Aqua L2A Global Swath Spatially-Resampled Brightness Temperatures data as input
  • An improved Antarctic land mask: Includes an updated ice shelf definition created by the National Ice Center Science Department in June 2011, and an updated shoreline developed from ENVISAT and RADARSAT imagery from October 2009 to April 2010. Also, this updated version no longer uses the Level-2A land flag and only uses the updated land mask for surface type classification in the southern hemisphere sea ice concentration algorithm.
  • Inclusion of ISO lineage metadata

Version 2 Processing and Algorithm History

V14-Stage1: Temporal coverage: 2010-08-27 (00:36) to 2011-10-03 (21:49)

Note: This version is currently unavailable. See Reprocessing of AMSR-E Sea Ice Products for details.

  • Includes an improved land mask for Antarctica, created from a National Ice Center (NIC) landmask shapefile. The NIC shapefile is the newest ice shelf definition, completed by NIC Science Department in June 2011. The shoreline was developed from ENVISAT and RADARSAT imagery from October 2009 until April 2010.

V13-Stage1: Temporal coverage: 2010-08-27 (00:36) to 2011-10-03 (21:49)

Changes included in this version are:

  • Updated the product maturity code to include R, for near-real-time data.
  • Corrected an error in the V12 code which produced the out-of-range value of -310 in the sea ice concentration difference field when data from the Bootstrap Basic Algorithm (BBA) were missing.

V12-Stage1: Temporal coverage: 2002-06-19 (00:29) to 2010-08-27 (00:37)

  • Corrected an error in the method for applying the multi-year sea ice mask that had caused large areas of Arctic to be erroneously masked in the Snow Depth on Sea Ice parameter. The multi-year sea ice mask and the snow melt mask are now stored within the AMSR-E/Aqua Daily L3 12.5 km Brightness Temperature, Sea Ice Concentration, & Snow Depth Polar Grids (AE_SI12) product. The AE_SI12 product is the only sea ice product with the Snow Depth on Sea Ice parameter, but all AMSR-E sea ice products use the same production code and therefore will be processed with the V12 algorithm.

V11-Stage1: Temporal coverage: 2002-06-19 (00:40) to 2010-04-24 (00:13)

  • Corrected an error in the snow depth over sea ice retrieval in the Southern Hemisphere. This error, introduced in V10, caused snow depth to be overestimated by a factor of about two. AE_SI12 is the only product with the Snow Depth on Sea Ice parameter, but all AMSR-E sea ice products use the same production code and will be processed with the V11 algorithm.

V10-Stage1: Temporal coverage: 2002-06-19 (00:29) to 2009-05-28 (00:41)

  • Modified the tie point tables for the Antarctic.

V09: Temporal coverage: 2008-09-21 (00:44) to 2009-01-26 (00:03)

  • A new sea ice version was implemented to validate sea ice. There were no changes to the science algorithm from T08 to V09.The only change was to the file name.

T08: Temporal coverage: 2002-06-19 (00:29) to 2008-09-21 (00:44)

  • The AMSR-E sea ice temperature grids were removed from the 25 km product because of inherent ambiguities between changes in the physical temperature of the ice and changes in the ice emissivity. Instead, the panel suggested that an AMSR-E sea ice drift product be developed. Also, this algorithm includes all modifications made in version T07.

T07: Data never produced using this algorithm version. Algorithm updates included the following:

  • Updated the product maturity code status to Transitional (T).
  • Updated the sea ice concentration parameters.
  • Converted the algorithm code to run on Linux. This version is not compatible with SGI IRIX.
  • Set the default system stacksize parameter to unlimited.
  • Added a shell script that is used during installation.
  • Added new flag values for the 12.5 km snow depth product such as:
  • 140 indicates multiyear sea ice
  • 150 indicates variability in snow depth
  • 160 indicates snow melt.

Version 1 Processing and Algorithm History

B06: Temporal coverage: 2006-03-16 (00:39) to 2008-07-06 (00:24)

  • Updates to accommodate the L2A version B07 format changes.

B05: Temporal coverage: 2005-09-05 (00:38) to 2006-03-16 (00:40)

This algorithm includes:

  • Incorporation of the TLSCF L2A B05 reader.
  • Calculation of Southern Hemisphere parameters based on the NASA Team 2 algorithm instead of the Bootstrap algorithm.
  • Modification of difference arrays in Southern Hemisphere; all difference arrays now reflect the difference in the Bootstrap algorithm from the stored NASA Team 2 algorithm.
  • Updates to error reporting.
  • Updates for local only Global Hydrology and Climate Center Science Investigator-led Processing System (GHCC-SIPS) HDF-EOS version 2.13 grid API (GDapi.c) to store the eccentricity squared projection parameter to 9 decimal places in the structural metadata.

B04: Temporal coverage: 2005-02-25 (00:39) to 2005-09-05 (00:38)

  • This algorithm adapts to the B04 L2A format changes.

B03: Temporal coverage: 2004-09-24 (00:03) to 2005-02-25 (00:39)

The following B03 algorithm changes apply only to data derived from the Bootstrap sea ice algorithm:

  • Uses the 37H GHz channel in the sea ice concentration algorithm.
  • Updates emissivity values.
  • Significantly updates the bootstrap sea ice concentration algorithm.
  • Adds brightness temperatures to threshold checks.
  • Modifies the brightness temperature upper limit value from 350 K to 320 K.
  • Also, a known issue exists in this version. In the HDF-EOS structural metadata, the eccentricity squared projection parameter is rounded to only four significant digits, whereas the program actually uses a value with seven significant digits (0.006694 vs. 0.006693883).

B02: Temporal coverage: 2002-06-18 (23:40) to 2004-09-24 (00:03)

  • First public version of data. The following B02 algorithm changes apply only to data derived from the Bootstrap sea ice algorithm:
  • Uses the full swath.
  • Updates emissivity values based on date.
  • Updates intercept parameters used in line-fitting routines.
  • Adds 37H GHz to the argument list for Southern Hemisphere routines.
  • Eliminates overlapping scans between passes.
  • Updates weather filter parameters.
  • Updates brightness temperature tie points for ice concentration.

B01: Original at-launch version of data.

AMSR-E/Aqua Daily L3 25 km Brightness Temperature & Sea Ice Concentration Polar Grids (AE_SI25)

Current Version: Version 3 (V003)

Maturity Details: V15-Stage 1

Temporal Coverage: 2002-06-01 (00:29) to 2011-10-04 (06:51)

Version Changes

Changes to the Version 3 algorithm for these data include:

  • Use of the most recent version (Version 3) of the AMSR-E/Aqua L2A Global Swath Spatially-Resampled Brightness Temperatures data as input
  • An improved Antarctic land mask: Includes an updated ice shelf definition created by the National Ice Center Science Department in June 2011, and an updated shoreline developed from ENVISAT and RADARSAT imagery from October 2009 to April 2010. Also, this updated version no longer uses the Level-2A land flag and only uses the updated land mask for surface type classification in the southern hemisphere sea ice concentration algorithm.
  • Inclusion of ISO lineage metadata

Version 2 Processing and Algorithm History

V14-Stage1: Temporal coverage: 2010-08-27 (00:36) to 2011-10-03 (21:49)

  • Note: This version is currently unavailable. See Reprocessing of AMSR-E Sea Ice Products for details.
  • Includes an improved land mask for Antarctica, created from a National Ice Center (NIC) landmask shapefile. The NIC shapefile is the newest ice shelf definition, completed by NIC Science Department in June 2011. The shoreline was developed from ENVISAT and RADARSAT imagery from October 2009 until April 2010.

V13-Stage1: Temporal coverage: 2010-08-27 (00:36) to present

Changes included in this version are:

  • Updated the product maturity code to include R, for near-real-time data.
  • Corrected an error in the V12 code which produced the out-of-range value of -310 in the sea ice concentration difference field when data from the Bootstrap Basic Algorithm (BBA) were missing.

V12-Stage1: Temporal coverage: 2002-06-19 (00:29) to 2010-08-27 (00:37)

  • Corrected an error in the method for applying the multi-year sea ice mask that had caused large areas of Arctic to be erroneously masked in the Snow Depth on Sea Ice parameter. The multi-year sea ice mask and the snow melt mask are now stored within the AMSR-E/Aqua Daily L3 12.5 km Brightness Temperature, Sea Ice Concentration, & Snow Depth Polar Grids (AE_SI12) product. The AE_SI12 product is the only sea ice product with the Snow Depth on Sea Ice parameter, but all AMSR-E sea ice products use the same production code and therefore will be processed with the V12 algorithm.

V11-Stage1: Temporal coverage: 2002-06-19 (00:40) to 2010-04-24 (00:13)

  • Corrected an error in the snow depth over sea ice retrieval in the Southern Hemisphere. This error, introduced in V10, caused snow depth to be overestimated by a factor of about two. AE_SI12 is the only product with the Snow Depth on Sea Ice parameter, but all AMSR-E sea ice products use the same production code and will be processed with the V11 algorithm.

V10-Stage1: Temporal coverage: 2002-06-19 (00:29) to 2009-05-28 (00:41)

  • Modified the tie point tables for the Antarctic.

V09: Temporal coverage: 2008-09-21 (00:44) to 2009-01-26 (00:03)

  • A new sea ice version was implemented to validate sea ice. There were no changes to the science algorithm from T08 to V09.The only change was to the file name.

T08: Temporal coverage: 2002-06-19 (00:29) to 2008-09-21 (00:44)

  • The AMSR-E sea ice temperature grids were removed from the 25 km product because of inherent ambiguities between changes in the physical temperature of the ice and changes in the ice emissivity. Instead, the panel suggested that an AMSR-E sea ice drift product be developed. Also, this algorithm includes all modifications made in version T07.

T07: Data never produced using this algorithm version. Algorithm updates included the following:

  • Updated the product maturity code status to Transitional (T).
  • Updated the sea ice concentration parameters.
  • Converted the algorithm code to run on Linux. This version is not compatible with SGI IRIX.
  • Set the default system stacksize parameter to unlimited.
  • Added a shell script that is used during installation.
  • Added new flag values for the 12.5 km snow depth product such as:
  • 140 indicates multiyear sea ice
  • 150 indicates variability in snow depth
  • 160 indicates snow melt.

Version 1 Processing and Algorithm History

B06: Temporal coverage: 2006-03-16 (00:39) to 2008-07-06 (00:24)

  • Updates to accommodate the L2A version B07 format changes.

B05: Temporal coverage: 2005-09-05 (00:38) to 2006-03-16 (00:40)

This algorithm includes:

  • Incorporation of the TLSCF L2A B05 reader.
  • Calculation of Southern Hemisphere parameters based on the NASA Team 2 algorithm instead of the Bootstrap algorithm.
  • Modification of difference arrays in Southern Hemisphere; all difference arrays now reflect the difference in the Bootstrap algorithm from the stored NASA Team 2 algorithm.
  • Updates to error reporting.
  • Updates for local only Global Hydrology and Climate Center Science Investigator-led Processing System (GHCC-SIPS) HDF-EOS version 2.13 grid API (GDapi.c) to store the eccentricity squared projection parameter to 9 decimal places in the structural metadata.

B04: Temporal coverage: 2005-02-25 (00:39) to 2005-09-05 (00:38)

  • This algorithm adapts to the B04 L2A format changes.

B03: Temporal coverage: 2004-09-24 (00:03) to 2005-02-25 (00:39)

The following B03 algorithm changes apply only to data derived from the Bootstrap sea ice algorithm:

  • Uses the 37H GHz channel in the sea ice concentration algorithm.
  • Updates emissivity values.
  • Significantly updates the bootstrap sea ice concentration algorithm.
  • Adds brightness temperatures to threshold checks.
  • Modifies the brightness temperature upper limit value from 350 K to 320 K.
  • Also, a known issue exists in this version. In the HDF-EOS structural metadata, the eccentricity squared projection parameter is rounded to only four significant digits, whereas the program actually uses a value with seven significant digits (0.006694 vs. 0.006693883).

B02: Temporal coverage: 2002-06-18 (23:40) to 2004-09-24 (00:03)

First public version of data. The following B02 algorithm changes apply only to data derived from the Bootstrap sea ice algorithm:

  • Uses the full swath.
  • Updates emissivity values based on date.
  • Updates intercept parameters used in line-fitting routines.
  • Adds 37H GHz to the argument list for Southern Hemisphere routines.
  • Eliminates overlapping scans between passes.
  • Updates weather filter parameters.
  • Updates brightness temperature tie points for ice concentration.

B01: Original at-launch version of data.

AMSR-E/Aqua Daily L3 Global Snow Water Equivalent EASE-Grids (AE_DySno)

Current Version: Version 2 (V002)

Maturity Details: V10-Stage 1

Temporal Coverage: 2010-08-27 (01:26) to 2011-10-3 (21:49)

Version Changes

Updated the product maturity code to include R, for near-real-time data. There were no changes to the science algorithm in this version.

Version 2 Processing and Algorithm History

V09-Stage1: Temporal coverage: 2002-06-19 (00:29) to 2010-08-27 (00:37)

Changes included in this version are:

  • Updated the product maturity code status to Validated. There are no algorithm changes from T08 to V09.
  • Corrected file start/end times in the metadata to accurately reflect only descending orbits.
  • Removed version numbers from ancillary file names.
  • Updated the ancillary file Combined_SnowImp_and_LOCI_mask_EASE_Both.

T08: Temporal coverage: 2002-06-19 (00:29) to 2008-12-01 (00:02)

  • Changes included in this version are:
  • Updated the product maturity code status to Transitional (T). There are no algorithm changes from version B07 to T08.
  • Converted the algorithm code to run on Linux. This version is not compatible with SGI IRIX.
  • Improved input list error checking.
  • Set the default system stacksize parameter to unlimited.

Version 1 Processing and Algorithm History

B07: Temporal coverage: 2006-03-31 (00:46) to 2008-07-06 (00:24)

  • Added the scale factor attribute to Snow Water Equivalent arrays.

B06: Temporal coverage: 2006-03-16 (00:39) to 2006-03-31 (00:46)

  • Updates to accommodate the L2A version B07 format changes.

B05: Temporal coverage: 2006-01-14 (12:20) to 2006-03-16 (00:40)

This algorithm includes:

  • Updates to the forest cover ancillary files. Two MODIS products are now used to help correct for forest attenuation.
  • The daily product retrievals are now performed on the AMSR-E individual Tb samples, which are then averaged to the EASE-Grid 25x25 km Northern and Southern Hemisphere projection grid.
  • Retrievals are calibrated for snow depth with a snow density climatology file used to convert snow depth to Snow Water Equivalent (SWE).

B04: Temporal coverage: 2005-02-25 (00:39) to 2006-01-14 (12:20)

  • This algorithm adapts to the B04 L2A format changes.

B03: Temporal coverage: 2004-11-25 (12:15) to 2005-02-25 (00:39)

This algorithm:

  • Contains ancillary file updates.
  • Uses satellite attitude information.
  • Adds brightness temperature limit checks.
  • Eliminates checks for rain, cold rain, and wet snow.
  • Eliminates explicit definition of xdim and ydim in the grid setup.

B02: Temporal coverage: 2002-06-19 (00:29) to 2004-11-28 (00:46)

Changes to this algorithm include:

  • The number of pixels per scan changed from 196 to 243 (the full swath width).
  • Updated land and surface type classification parameters and regression parameters.
  • Updated brightness temperature quality assessment to prevent out-of-bounds brightness temperatures from being gridded.
  • A new frozen ground classification.
  • Using the difference of the 10.6V GHz and 18.0V GHz as the only criteria for defining Radio Frequency Interference (RFI). If the difference is greater than or equal to 5.0, the pixel is flagged as contaminated with RFI.
  • Upgrades to the surface type classification to indicate combinations of surface types.

B01: Original at-launch version of data.

AMSR-E/Aqua 5-Day L3 Global Snow Water Equivalent EASE-Grids (AE_5DSno)

Current Version: Version 2 (V002)

Maturity Details: V10-Stage 1

Temporal Coverage: 2010-08-24 (00:55) to 2011-10-3 (00:23)

Version Changes

Updated the product maturity code to include R, for near-real-time data. There were no changes to the science algorithm in this version.

Version 2 Processing and Algorithm History

V09-Stage1: Temporal coverage: 2002-06-19 (00:29) to 2010-08-24 (00:06)

Changes included in this version are:

  • Updated the product maturity code status to Validated. There are no algorithm changes from T08 to V09.
  • Corrected file start/end times in the metadata to accurately reflect only descending orbits.
  • Removed version numbers from ancillary file names.
  • Updated the ancillary file Combined_SnowImp_and_LOCI_mask_EASE_Both.

T08: Temporal coverage: 2002-06-19 (00:29) to 2008-11-27 (00:27)

Changes included in this version are:

  • Updated the product maturity code status to Transitional (T). There are no algorithm changes from version B07 to T08.
  • Converted the algorithm code to run on Linux. This version is not compatible with SGI IRIX.
  • Improved input list error checking.
  • Set the default system stacksize parameter to unlimited.

Version 1 Processing and Algorithm History

B07: Temporal coverage: 2006-03-27 (00:21) to 2008-07-06 (00:24)

  • Added the scale factor attribute to Snow Water Equivalent arrays.

B06: Temporal coverage: 2006-03-12 (00:15) to 2006-03-27 (00:21)

  • Updates to accommodate the L2A version B07 format changes.

B05: Temporal coverage: 2006-01-11 (12:38) to 2006-03-12 (00:15)

This algorithm includes:

  • Updates to the forest cover ancillary files. Two MODIS products are now used to help correct for forest attenuation.
  • The daily product retrievals are now performed on the AMSR-E individual Tb samples, which are then averaged to the EASE-Grid 25x25 km Northern and Southern Hemisphere projection grid.
  • Retrievals are calibrated for snow depth with a snow density climatology file used to convert snow depth to Snow Water Equivalent (SWE).

B04: Temporal coverage: 2005-02-20 (00:20) to 2006-01-11 (12:39)

  • This algorithm adapts to the B04 L2A format changes.

B03: Temporal coverage: 2004-11-22 (00:33) to 2005-02-20 (00:21)

This algorithm:

  • Contains ancillary file updates.
  • Uses satellite attitude information.
  • Adds brightness temperature limit checks.
  • Eliminates checks for rain, cold rain, and wet snow.
  • Eliminates explicit definition of xdim and ydim in the grid setup.

B02: Temporal coverage: 2002-06-20 (00:23) to 2004-11-17 (00:15)

Changes to this algorithm include:

  • The number of pixels per scan changed from 196 to 243 (the full swath width).
  • Updated land and surface type classification parameters and regression parameters.
  • Updated brightness temperature quality assessment to prevent out-of-bounds brightness temperatures from being gridded.
  • A new frozen ground classification.
  • Using the difference of the 10.6V GHz and 18.0V GHz as the only criteria for defining Radio Frequency Interference (RFI). If the difference is greater than or equal to 5.0, the pixel is flagged as contaminated with RFI.
  • Upgrades to the surface type classification to indicate combinations of surface types.

B01: Original at-launch version of data.

AMSR-E/Aqua Monthly L3 Global Snow Water Equivalent EASE-Grids (AE_MoSno)

Current Version: Version 2 (V002)

Maturity Details: V10-Stage 1

Temporal Coverage: 2010-08-01 (00:49) to 2011-10-1 (00:36)

Version Changes

Updated the product maturity code to include R, for near-real-time data. There were no changes to the science algorithm in this version.

Version 2 Processing and Algorithm History

V09-Stage1: Temporal coverage: 2002-06-19 (00:29) to 2010-08-24 (00:06)

Changes included in this version are:

  • Updated the product maturity code status to Validated. There are no algorithm changes from T08 to V09.
  • Corrected file start/end times in the metadata to accurately reflect only descending orbits.
  • Removed version numbers from ancillary file names.
  • Updated the ancillary file Combined_SnowImp_and_LOCI_mask_EASE_Both.

T08: Temporal coverage: 2002-06-19 (00:29) to 2008-11-01 (00:38)

Changes included in this version are:

  • Updated the product maturity code status to Transitional (T). There are no algorithm changes from version B07 to T08.
  • Converted the algorithm code to run on Linux. This version is not compatible with SGI IRIX.
  • Improved input list error checking.
  • Set the default system stacksize parameter to unlimited.
Version 1 Processing and Algorithm History

B07: Temporal coverage: 2006-03-01 (00:33) to 2008-07-06 (00:24)

  • Added the scale factor attribute to Snow Water Equivalent arrays.

B06: Temporal coverage: 2006-03-16 (00:39) to 2006-03-31 (00:46)

  • Updates to accommodate the L2A version B07 format changes.

B05: Temporal coverage: 2006-01-01 (00:33) to 2006-03-01

This algorithm includes:

  • Updates to the forest cover ancillary files. Two MODIS products are now used to help correct for forest attenuation.
  • The daily product retrievals are now performed on the AMSR-E individual Tb samples, which are then averaged to the EASE-Grid 25x25 km Northern and Southern Hemisphere projection grid.
  • Retrievals are calibrated for snow depth with a snow density climatology file used to convert snow depth to Snow Water Equivalent (SWE).

B04: Temporal coverage: 2005-02-01 to 2006-01-01

  • This algorithm adapts to the B04 L2A format changes.

B03: Temporal coverage: 2004-11-01 to 2005-02-01

This algorithm:

  • Contains ancillary file updates.
  • Uses satellite attitude information.
  • Adds brightness temperature limit checks.
  • Eliminates checks for rain, cold rain, and wet snow.
  • Eliminates explicit definition of xdim and ydim in the grid setup.

B02: Temporal coverage: 2002-06-19 to 2004-11-01

Changes to this algorithm include:

  • The number of pixels per scan changed from 196 to 243 (the full swath width).
  • Updated land and surface type classification parameters and regression parameters.
  • Updated brightness temperature quality assessment to prevent out-of-bounds brightness temperatures from being gridded.
  • A new frozen ground classification.
  • Using the difference of the 10.6V GHz and 18.0V GHz as the only criteria for defining Radio Frequency Interference (RFI). If the difference is greater than or equal to 5.0, the pixel is flagged as contaminated with RFI.
  • Upgrades to the surface type classification to indicate combinations of surface types.

B01: Original at-launch version of data.

AMSR-E/Aqua Daily L3 6.25 km Sea Ice Drift Polar Grids (AE_SID)

Current Version: Version 1 (V001)

Maturity Details: B03

Temporal Coverage: 2011-05-30 (00:11) to 2011-10-03 (21:49)

Version Changes

Added browse imagery and reprocessed data to span entire AMSR-E mission.

Note: This version is currently unavailable due to reprocessing of AMSR-E Sea Ice Products. 

Version 1 Processing and Algorithm History

B02: N/A (The B02 algorithm was not publicly released).

B01: Temporal coverage: 2011-06-01 to 2011-10-03. Original version of data.