ASTER User's Guide - NASA

ASTER Users Handbook13.0. Frequently-Asked QuestionsThis section provides a representative sample of frequently-asked questions (FAQs) from usersrelating to various aspects of ASTER that were received both at JPL and LP-DAAC sinceASTER data were made publicly available in November of 2000. These FAQs have beenbroadly categorized in 10 groups:13.1 General ASTER13.2 ASTER Instrument13.3 ASTER Level-1 Data13.4 Acquiring and Ordering ASTER Data13.5 ASTER Metadata13.6 ASTER Higher-Level Products13.7 ASTER Expedited Data Sets13.8 ASTER-Related Algorithms13.9 ASTER Documentation13.10 HDF-EOS Data Format13.1 General ASTERCould you give a brief description of ASTER and its sensor systems?The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of 5instruments aboard the Terra platform that was launched in December, 1999. ASTER was builtby a consortium of Japanese government, industry, and research groups. It has three spectralbands in the visible near-infrared (VNIR), six bands in the short-wave infrared (SWIR), and fivebands in the thermal infrared (TIR) regions, with 15, 30, and 90 meters ground resolutionrespectively. This combination of wide spectral coverage and high spatial resolution allowsASTER to discriminate amongst a large variety of surface materials, ideal for geological studies.The VNIR subsystem is specifically endowed with a backward-viewing telescope for highresolutionstereoscopic observation in the along-track direction. The ASTER instrument isunique in two respects: one, it provides multispectral thermal infrared data of high spatialresolution, and also the highest spatial resolution surface spectral reflectance, temperature andemissivity data of all the Terra instrument sensor systems; and two, because of its limited dutycycle, data are acquired to fulfill on-demand data acquisition requests. The ASTER dataproducts include relative spectral reflectance and emissivity, surface radiance, temperature,reflectance and emissivity, brightness temperature-at-sensor, and digital elevation models.ASTER data are expected to contribute to a wide array of application areas including, geologyand soils, vegetation and ecosystem dynamics, hazards monitoring (volcanoes, wildfires, floods,landslides, and coastal erosion), land surface climatology, hydrology, and land cover change.Additional details regarding the instrument, data products etc. can be accessed from:http://asterweb.jpl.nasa.gov/default.htmWhat are the sizes of ASTER pixels?62