Digital Orthophoto Quadrangles (DOQQ)
A digital orthophoto quadrangle (DOQ) is a computer-generated image of an aerial photograph in which image displacement caused by terrain relief and camera tilts has been removed.
DOQQ images avaialbe on the DNR GIS Data Clearinghouse are Color-infrared (CIR) with a 1-meter ground resolution covering an area measuring 3.75-minutes longitude and 3.75-minutes latitude. Each image has between 50 and 300 meters of overedge beyond the latitude and longitude corner crossess embedded in the image to faciliate tonal matching and moasaicking adjacent images.
A DOQ can be incorporated into any geographic information system (GIS) that can manipulate raster images. It can function as a cartographic base for displaying, generating, and modifying associated digital data.
Joint Funding Agrrements (JFAs) with various other agencies funded the DOQQ data acquisistion for 1994, 1999, and 2006.
Geographic Coordinate System
UTM, Zone 17, Meters, Datum NAD83
Compressed Format for DOQQ Data
1994, 1999 - MrSid; 2006 - JPEG2000
ESRI ArcView 3.x users will need to download a free plug-in extension from LizardTech, GeoJP2 ArcView Plugin, to view JPEG2000 image data. For other software programs, please consult your particular software's help to determine compatibility with this format and any required software updates and/or plugins.
Status map of available DOQQ
Download Available DOQQ
Data is available for download at no cost from DNR's GIS Data Clearinghouse. Refer to DNR GIS DNR Clearinghouse for availability.