ASTER-Derived 30-Meter-Resolution Digital Elevation Models of Afghanistan Peter G. Chirico and Michael B. Warner Data Series 318 2007 U.S. Department of the Interior U.S. Geological Survey Abstract: The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is an imaging instrument aboard the Terra satellite, launched on December 19, 1999, as part of the National Aeronautics and Space Administration's (NASA) Earth Observing System (EOS). The ASTER sensor consists of three subsystems: the visible and near infrared (VNIR), the shortwave infrared (SWIR), and the thermal infrared (TIR), each with a different spatial resolution (VNIR, 15 meters; SWIR, 30 meters, TIR 90 meters). The VNIR system has the capability to generate along-track stereo images that can be used to create digital elevation models (DEMs) at 30-meter resolution. Currently, the only available DEM dataset for Afghanistan is the 90-meter-resolution Shuttle Radar Topography Mission (SRTM) data. This dataset is appropriate for macroscale DEM analysis and mapping. However, ASTER provides a low cost opportunity to generate higher resolution data that can be used for landform classification, geologic structure analysis, and coal resource assessments. For this publication, ASTER scenes were and processed and mosaicked to generate 36 DEMs which were created and extracted using PCI Geomatics' OrthoEngine 3D Stereo software. The ASTER images were geographically registered to Landsat data with at least 15 accurate and well distributed ground control points with a root mean square error (RMSE) of less that one pixel (15 meters). An elevation value was then assigned to each ground control point by extracting the elevation from the 90-meter SRTM data. The 36 derived DEMs demonstrate that the software correlated on nearly flat surfaces and smooth slopes accurately. Larger errors occur in cloudy and snow-covered areas, lakes, areas with steep slopes, and southeastern-facing slopes. In these areas, holes, large pits, and spikes were generated by the software during the correlation process and the automatic interpolation method. To eliminate these problems, overlapping DEMs were generated and filtered using a progressive morphologic filter. The quadrangles used to delineate the DEMs in the publication were derived from the Afghan Geodesy and Cartography Head Office's (AGCHO) 1:100,000-scale maps series quadrangles. Each DEM was clipped and assigned a name according to the associated AGCHO quadrangle name. The geospatial data included in this publication are intended to be used with any GIS software packages including, but not limited to, ESRI's ArcGIS and ERDAS IMAGINE. ---------------------------------------------- This DVD includes the following data structure. ---------------------------------------------- DIRECTORY IMGs This folder includes the 36, 30m resolution ASTER DEMs stored in Erdas Imagine (.img) format and projected in UTM Zone 42 North, WGS 84 Datum. ESRI_e00_Files This folder includes the 36, 30m resolution ASTER DEMs stored in ESRI interchange (.e00) format and projected in UTM Zone 42 North, WGS 84 Datum. Index_Maps Afg_ASTER_Index_Map.pdf – Index map stored in Adobe Acrobat (PDF) format displaying the locations and quadrangle numbers of available ASTER DEMs included in this publication. Also contains said image in jpeg format. Afg_Shaded_Relief_Map.pdf - Shaded relief map produced from the ASTER DEMs for this publication. Map is stored in PDF format. Also contains said image in jpeg format. IMAGES Image files used for this data series' webpage. METADATA ASTER_DEMs_Metadata – FGDC compliant metadata file for the ASTER DEMs. SHAPEFILES Afg_ASTER_DEM_Index – An index shapefile of all available 30m-resolution ASTER DEMs of Afghanistan. Afg_ASTER_Index.zip - Zipped version of the shapefile to facilitate data transfer. index.html The webpage associated with this data series. README.txt This file. Contact.txt - Text-only file that provides scientific contact information for any questions regarding this publication. Disclaimer.txt - Text-only standard disclaimer for this publication.