Digital Orthophoto Quarter-Quadrangles from 1999, Niwot Ridge LTER Project Area, Colorado

(SEE SUPPLEMENTAL INFORMATION SECTION FOR FILE-SPECIFIC INFORMATION.)Digital orthophoto quarter-quads are now available for most of the United States and its Territories. Quarter-quad DOQs cover an area measuring 3.75-minutes longitude by 3.75-minutes latitude. Quarter-quad DOQs are available in both Native and GeoTIFF formats. Native format consists of an ASCII keyword header followed by a series of 8-bit binary image lines for B/W and 24-bit band-interleaved-by-pixel (BIP) for color. DOQs in native format are cast to the Universal Transverse Mercator (UTM) projection and referenced to either the North American Datum (NAD) of 1927 (NAD27) or the NAD of 1983 (NAD83). GeoTIFF format consists of a georeferenced Tagged Image File Format (TIFF), with all geographic referencing information embedded within the .tif file. DOQs in GeoTIFF format are cast to the UTM projection and referenced to NAD83. The average file size of a B/W quarter quad is 40-45 megabytes, and a color file is generally 140-150 megabytes. Quarter-quad DOQs are distributed on CD-ROM, DVD, and File Transfer Protocol (FTP) as uncompressed files.A downloadable software is available (DOQQ-to-GeoTIFF conversion) which will convert a DOQ image from Native to GeoTIFF format in either NAD27 or NAD83. NOTE: This EML metadata file does not contain important geospatial data processing information. Before using any NWT LTER geospatial data read the arcgis metadata XML file in either ISO or FGDC compliant format, using ArcGIS software (ArcCatalog > description), or by viewing the .xml file provided with the geospatial dataset.