NASA's Land Processes Distributed Active Archive Center (LP DAAC) uses the Science Scalable Scripts-based Science Processor for Missions (S4PM) processing system to produce all Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Level 1, -2, and -3 products. Currently, all ASTER Level 1 and -2 products are only available in the Hierarchical Data Format (HDF). As part of the S4PM 5.4.3 maintenance package release on June 4, 2008, users may select GeoTIFF as an alternative format, while HDF remains the default. Presently, only ASTER Level 3 products are offered in GeoTIFF format.
The image data are converted to GeoTIFF files with a .tif extension. All the metadata and ancillary files are converted to text files with a .txt extension. The single external metadata file is available in its original form with a .met extension. All these files are packaged in a single compressed file with a .zip extension.