This directory contains Digital Orthophotography Quarter Quadrangle images. These files were supplied the USDA - Natural Resource Conservation Service. These files contain both a *.bsq (band sequential) file and a *.hdr (header) file. Both files are need in order to bring the DOQQ in as a geo-referenced image. Any questions pertaining to metadata, please see the 1metadata.txt file. CAUTION - These files are VERY large with the average file size reaching 35 MB. Download time will be slow. Nameing convention is a variant of the USGS 7.5 minute quadrangle nameing convention. In the file 47101a6_3 the first 7 characters (xxxxxx_3) respond to the USGS naming convention of Latitude (xx101a6_3) Longitude (47xxxa6_3) and grid number (47101xx_3). The dash indicates a finer scale than 1:24,000, with the number designating which quarter of the 1:24,000 scale quad this file is located in. The numbers start in the NW quarter and proceede clockwise to the SW: ------------- | | | | 1 | 2 | | | | ------------- | | | | 4 | 3 | | | | -------------