COMPRESSED DIGITAL ORTHOPHOTO QUADRANGLES (COQs)

Source:   Nebraska Department of Natural Resources Processed by:   Data Bank      (JH) A Compressed DOQ, also known as COQ, is a Digital Orthophoto Quarter Quadrangle image that has been compressed using JPEG format. Since JPEG is a "lossy" image compression format, a COQ will have slightly less color separation or clarity than that of a DOQ. However, its resolution (1-meter pixel size) remains the same. The COQ requires about 2 MB to 4 MB of storage space per 3.75- minute or quarter quadrangle region. Since a COQ image is compressed, it associated header file should also be retreived separtately. The COQs are also available in World File Format. Follow instructions below: Retrieval of COQs (1999) The Nebraska Department of Natural Resources in cooperation with the U. S. Geological Survey, developed DOQs based on 1999 NAPP imagery and second generation of 10-meter DEMs. The 1999 DOQs are developed in two coordinate systems, UTM and the State Plane, referenced to North American Datum of 1983 (NAD83) with coordinates published both in meters and feet. Metadata of 1999 UTM DOQ/COQs Following options are available to retrieve COQs. DNR Map Interface - To identify and download Quarter Quadrangles (COQQs) click on both active and visible layers of the Quarter Quad (COQQ) dataset and click the "refresh map" button on the interactive map. - Zoom in using the magnifing glass tool with the plus sign, then click hyperlink(lightning bolt) from the tool box and click the proper quadrangle to download the COQQs. Provides access to both 1993 and 1999 COQQs. DNR Text Interface - Including USGS/DNR COQs & FSA Imagery UTM Projections (Zone 13, 14 & 15) - FTP site Nebraska State Plane Coordinate System (FIPS Zone 2600) - FTP site NOTE: The FTP sites have directories referenced to latitude/longitude. Each 1999 COQ (3.5 minute quarter-quadrangle, 1-meter ground resolution, 1:12,000 scale) requires about 2MB to 3MB of storage space. The transmission of coverage may take 25 minutes or more at 56KB and low-speed Internet links. The transmission of data at lower speeds is not recommended. Quadrangle Identifcation Map (DNR & FSA) (28" X 45") Shapefile of DNR & FSA numbering scheme Software for COQs Retrieval of COQs (1993) The 1993 COQs, (3.5 minute, quarter-quadrangle, 1-meter, 1:12,000 scale) are available on-line in NAD 83 and UTM projections. These COQs are accessible over the Internet through the Nebraska Department of Natural Resources website, and as well as its FTP site. Following options are available to retrieve COQs DNR Map Interface - To identify and download Quarter Quadrangles (COQQs) click on both active and visible layers of the Quarter Quad (COQQ) dataset and click the "refresh map" button on the interactive map. - Zoom in using the magnifing glass tool with the plus sign, then click hyperlink(lightning bolt) from the tool box and click the proper quadrangle to download the COQQs. Provides access to both 1993 and 1999 COQQs. DNR Text Interface - Including USGS/DNR COQs & FSA Imagery DNR FTP Site NOTE: The FTP sites have directories referenced to latitude/longitude. The transmission of COQs over low-speed connections may take 25 minutes or more per COQ. The transfer of data is generally not recommeded for communications speeds less than 56 KB/second. User Request Comments and Suggestions   [ DNR Home ] [ Administration/Legal ] [ Surface Water ] [ Ground Water ] [ Data Bank ] [ Field Offices ] [ Planning & Assistance ] [ Floodplain & Dam Safety ] [ Resource Mgt Funds ] [ Site Index/Table of Contents ] [ Contact Us ] [ Need Help! ] [ Newsletter ] [ Staff Directory ] [ DNR Frequently Used Forms ] [ Work For Us ] [ Links ] [ Search This Site! ] [ Frequently Used Sites ] [ Security, Privacy & Accessibility Policy ] [ State of Nebraska ]