The USGS DOQ (digital orthophoto quad) covers of a 7.5’ quadrangle. It has very high spatial resolution, and each image requires about 50 Mb of storage if black and white and about 150 MB if color.

The image must be in a standard format like GEOTIFF file.

Once loaded, the DOQQ behaves like any other image.

Many states now have free USGS DOQQs available on line, often in formats like MrSid.

Last revised 4/29/2018