2005 Illinois Digital Orthophoto Quarter Quadrangle Data

Data

Summary

Illinois National Aerial Photography Program (NAPP) Digital Orthophotography quarter Quadrangle (DOQ) data have been created for 96 counties in two projections. These are Illinois Universal Transverse Mercator (UTM) with a NAD83 datum and State Plane (SP) with a NAD83 datum. This data collection excludes the counties of Cook, DuPage, Kane, Lake, McHenry, and Will in northeastern Illinois. Imagery was collected using NAPP specifications using black and white film during the leaf-off period of spring, 2005 at a 1.5 foot by 1.5 foot (half meter) resolution. Programmatic details for Illinois NAPP data were outlined in Illinois GIS Notes, Winter 2005.

Metadata

2005_SPCS26971.xml - State Plane East, NAD83

2005_SPCS26972.xml - State Plane West, NAD83

2005_UTM15.xml - UTM Zone 15, NAD83

2005_UTM16.xml - UTM Zone 16, NAD83

Data

Compressed Data

Data files are offered as LizardTech's MrSID Generation 2 .sid files. Target compression ratio is 10:1; one compressed file is roughly 18 megabytes in size.

A statewide collection of both 2005 Chicago Urban Area data and 2005 NAPP (60 Gigabytes) data requires about 100 Gigabytes of storage space. We do not plan to distribute compressed data files by any other means (cd-rom, zip drives, portable drives, ftp download, etc).

Illinois 2005 compressed NAPP DOQ data are available free-of-charge via:

a List of Counties for UTM (3,866 files) data download , or
a List of Counties for SP (3,929 files) data download.

Uncompressed Data

An ArcIMS web service has been created for the Universal Transverse Mercator data collections from the original GeoTIFF files loaded into ArcSDE.

Contact the Illinois State Library(link is external) to obtain indiviual, uncompressed Illinois 2005 orthoimagery files. Note that one statewide coverage of uncompressed 2005 Chicago Urban Area data and 2005 NAPP (680 to 690 Gigabytes) data would require about 1 Terabyte of storage space.