ASTER User's Guide - NASA

ASTER Users Handbookcorrection coefficients and radiometric calibration coefficients calculated and appended but notapplied.Level-1A datasets also include corrections for the SWIR parallax, and intra- and inter-telescoperegistration information. ASTER Level-1A data is produced at the Ground Data System (GDS)in Tokyo, Japan, and sent to the EROS Data Center's (EDC) Distributed Active Archive Center(DAAC) for archiving, distribution, and higher-level processing.Does ASTER Level-1A dataset have associated browse images?There are 3 separate browse files (one each for VNIR, SWIR and TIR) along with an ASTERLevel-1A dataset that can interactively be viewed (through the View Image button) and/orordered via the EOS Data Gateway (EDG). On occasions there may only be data derived fromone or two sensor(s). At such times there will not be all three browse images. Each browse filecan be ordered via the EDG. The browse files can also be downloaded as an UNIX tar file.Can you provide details (format, image dimensions) of the Level-1A browse files?The ASTER Level-1 Browse Data Product contains 1-scene of image data generated based onthe Level-1A data with similar radiometric corrections and mis-registration corrections appliedto Level-1B data. All image data (VNIR, SWIR, TIR) are 24-bit JPEG compressed imagesstored in an HDF file in RIS24 objects. Refer to Table 2 in this Handbook, which provides themain characteristics of the Level-1A browse images.What is an ASTER Level-1B dataset?The ASTER Level-1B product contains radiometrically calibrated and geometrically coregistereddata for all the channels acquired previously through the telemetry streams of the 3different telescopes in Level-1A. This product is created by applying the radiometric calibrationand geometric correction coefficients to the Level-1A data. Both intra-telescope and intertelescoperegistration corrections have also been applied relative to the reference band of eachsub-system. The Level-1B product offers the same number of bands at the same resolution as theLevel-1A product. Level-1B data are required as the input for generating higher level-2geophysical products. On the EDG, the View Image button allows the L1B granule to map backto the L1A’s browse (assuming the parent L1A granule exists in the inventory). These Level-1Bdata are produced at the Ground Data System (GDS) in Tokyo, Japan, and sent to the EROSData Center's (EDC) Distributed Active Archive Center (DAAC) for archiving, distribution, andhigher-level processing.Does ASTER Level-1B dataset have associated browse images?There are no browse images produced from ASTER Level-1B datasets. The “View Image”button on the EDG for an ASTER L1B dataset (when active) maps back to an ASTER Level-1Abrowse. The same caveats that apply to Level-1A browse apply to Level-1B browse also.Why is the “View Image” button for my ASTER Level-1B dataset inactive?64