The National Map Seamless Server, Earth Resources Observation and Science (EROS)
Landsat Orthoimagery Mosaic FAQ
Q. What is the Landsat Orthoimagery Mosaic product A. Orthoimagery combines the image characteristics of a photograph with the geometric qualities of a map. The Landsat Orthoimagery Mosaic orthoimagery database contains Landsat Thematic Mapper imagery for the conterminous United States. The more than 700 Landsat scenes have been resampled to a 1-arc-second (approximately 30-meter) sample interval in a geographic coordinate system using the North American Horizontal Datum of 1983. Three bands have been selected from the eight spectral bands available for each frame. These are bands 4 (near-infrared), 3 (red), and 2 (green), typically displayed as red, green, and blue, respectively. The image is a full-resolution (spectral and spatial), 24-bit color-infrared composite that simulates color infrared film as a "false color composite".These data have been created as a result of the need for having geospatial data immediately available and easily accessible in order to provide geographic reference for Federal, State, and local emergency responders, as well as for homeland security efforts. Orthoimages also serve a variety of purposes, from interim maps to field references for earth science investigations and analysis. The digital orthoimage is useful as a layer of a geographic information system. This data can be used to provide reference information for Web browsers and for map applications at a scale of 1:100,000 or smaller. Larger scale orthoimagery such as digital orthophoto quadrangles will be more accurate, but often at the expense of timely updates. Q.What are the specifications of the Landsat Orthoimagery Mosaic product A.
Q. What formats are available A. TIFF is a GeoTiff (.tif and .tfw files included)Q. What is the coverage area A. The coverage area is the conterminous US. |
U.S. Department of the Interior |
U.S. Geological Survey
URL: http://seamless.usgs.gov/faq/landsat_faq.php
Page Contact Information: webmapping@usgs.gov
Page Last Modified: November 07, 2007
