This demonstration utilizes Digital Orthophoto Quadrangle (DOQ) data supplied by the United States Geological Survey (USGS). DOQ images are derived from aerial photographs that have been digitized and then rectified to an orthographic projection, thus combining the visual properties of a digital image with the geometric properties of a map. The original data set used here is a mosaic of thirty-six 1 meter/pixel resolution DOQ quarterquad images depicting Washington, DC and the surrounding suburbs.
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Click HERE for additional map data.
Last updated February 3, 1995.
Calvin J. Hamilton (cjhamil@lanl.gov) Jonathan N. Bradley (bradley@lanl.gov)