MAPPING PARTS OF THE TOQUIMA AND TOIYABE RANGES IN NEVADA USING DEM ALONG WITH ASTER AND ALI REMOTE SENSING DATA

The purpose of this study was to apply satellite remote sensing imagery combined with digital elevation data to map geologic units and structures exposed in the Toquima and Toiyabe ranges near Kingston, Nevada. This area is well suited for this type of research because of the abundance of phyllosilicate-bearing rock, carbonates, and volcanic units. Two types of remote sensing data sets were used: imagery from the ASTER (Advanced Spaceborne Thermal Emission and Reflectance Radiometer) operating on the Earth Observation System Terra satellite; and data from the EO-1 (Earth Observer 1) ALI (Advanced Land Imager) satellite. Both satellite sensors measure surface radiance in the VNIR (visible near-infrared) and SWIR (short wave infrared) spectral ranges.

Prior to image analysis, layer stacking of the VNIR and SWIR bands and masking of snow and vegetation were necessary to eliminate interference and facilitate use of spectral profiling. Next, band math ratios and analysis of spectral profiles were utilized to differentiate geologic units. Structures were mapped by applying shaded relief topography to a DEM (digital elevation model). Finally, we created a three-dimensional model exhibiting the geologic units and structures within the Toquima and Toiyabe ranges by draping the ASTER and ALI remote sensing results over a three-dimensional DEM of the region. Preliminary results of the comparison between use of ASTER and ALI data to map geologic units will be presented at the conference along with the results of ASTER and DEM mapping.