Terra ASTER Surface Emissivity band 14 data from the AST_05 product over Baffin Island, Canada between March 1, 2000 and November 30, 2013.View full-size image
The Terra Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Surface Emissivity (AST_05) is produced using the Temperature/Emissivity Separation (TES) algorithm for the five Thermal Infrared (TIR) 90 meter bands, acquired during the day or night. The product is comprised of per-pixel emissivity measurements generated over land in addition to embedded metadata and quality assurance data planes.
The Science Scalable Scripts-based Science Processor for Missions (S4PM) Version 3.4 algorithm has additional input data options that provide better input data coverage (simultaneously acquired MODIS data versus 6-hourly modeled NCEP input data) and consequently more accurate Level 2 output data. The updated algorithm includes the following improvements:
Starting June 23, 2021, radiometric calibration coefficient Version 5 (RCC V5) will be applied to newly observed ASTER data and archived ASTER data products. Details regarding RCC V5 are described in the following journal article.
Tsuchida, S., Yamamoto, H., Kouyama, T., Obata, K., Sakuma, F., Tachikawa, T., Kamei, A., Arai, K., Czapla-Myers, J.S., Biggar, S.F., and Thome, K.J., 2020, Radiometric Degradation Curves for the ASTER VNIR Processing Using Vicarious and Lunar Calibrations: Remote Sensing, v. 12, no. 3, at https://doi.org/10.3390/rs12030427.
As of December 15, 2021, the LP DAAC has implemented changes to ASTER PGE Version 3.4, which will affect all ASTER Level 2 on-demand products. Changes include:
Additionally, Climatology, which is one of the inputs for Ozone and Moisture, Temperature and Pressures (MTP) will be removed from the Earthdata Order Form. It has been observed that PGEs generated with Climatology as an input yield noticeable differences statistically during image and spectral analysis. Climatology will continue to be used as the final default if neither of the first two selectable options are available for Ozone and MTP. Users can check the OPERATIONALQUALITYFLAGEXPLANATION field in the metadata or the output file for atmospheric parameters that were applied.
|File Size||~9 MB|
|Temporal Extent||2000-03-04 to Present|
|Coordinate System||Universal Transverse Mercator (UTM)|
|Datum||World Geodetic System (WGS84)|
|File Format||HDF-EOS or GeoTIFF|
|Geographic Dimensions||~60 km x 60 km|
|Number of Science Dataset (SDS) Layers||5|
|Columns/Rows||700 x 800|
|Pixel Size||90 m|
|SDS Name||Description||Units||Data Type||Fill Value||No Data Value||Valid Range||Scale Factor|
|TIR_Band10||90 meter resolution TIR Band 10 (8.125 to 8.475 µm)||N/A||16-bit unsigned integer||N/A||N/A||0 to 65535||0.001|
|TIR_Band11||90 meter resolution TIR Band 11 (8.475 to 8.825 µm)||N/A||16-bit unsigned integer||N/A||N/A||0 to 65535||0.001|
|TIR_Band12||90 meter resolution TIR Band 12 (8.925 to 9.275 µm)||N/A||16-bit unsigned integer||N/A||N/A||0 to 65535||0.001|
|TIR_Band13||90 meter resolution TIR Band 13 (10.25 to 10.95 µm)||N/A||16-bit unsigned integer||N/A||N/A||0 to 65535||0.001|
|TIR_Band14||90 meter resolution TIR Band 14 (10.95 to 11.65 µm)||N/A||16-bit unsigned integer||N/A||N/A||0 to 65535||0.001|
There are three groups of ancillary data inputs used in the atmospheric correction of ASTER Level 2 products:
The AST_05 products do not yet include the OPERATIONALQUALITYFLAGEXPLANATION field in the metadata file to indicate if a fall back has occurred and identify which input source was used to generate the Level 2 product files. A future release will include this metadata attribute information.