Pima County Geographic Information Systems

Maps and Drawings

BLM Arizona Imagery Mosaic

The BLM Arizona Imagery Mosaic includes over 8,000 images. Each source image has between 50 and 300 meters of overedge image beyond the latitude and longitude corner crosses embedded in the image. For this interactive map, the overedge has been clipped off and the images have been georeferenced to align with each other in a seamless mosaic grid. Due to variations in the individual photos, the seams are often visible on the Arizona map.

BLM Arizona Imagery Mosaic Metadata

The BLM Arizona Imagery Mosaic is referenced to the NAD 83 UTM projection, Zone 12.

More metadata for the imagery itself and related photo index layers includes:

• BLM Arizona Imagery Mosaic - Various Sources and Image Types

• The BLM Arizona Imagery Mosaic - TIFF Photo Index layer is a grid showing the area covered by each of the original TIFF format orthophotos. Picking a point on the PimaMaps - Arizona map shows a map tip with the Quad name and photo date where available.

• The BLM Arizona Imagery Mosaic - ECW Photo Index layer is a grid showing the area covered by the compressed ECW orthophotos. Since ECW files are more highly compressed than TIFF, the ECW files cover a larger area than the original TIFF format orthophotos.

Credits

We thank the BLM GIS Incident Management Team for clipping and mosaicing the photos from the U.S. Geological Survey and various other sources, and the Arizona State Cartographer's Office for duplicating the stacks of CDs to make them available to us.