Digital Orthophoto Quarter Quads (DOQQs) from USGS are aerial photographs of 1 meter/pixel resolution.

Digital orthophotos are rectified to remove distortion effects from camera lenses, tip, and tilt as well as from terrain relief and scale.  They serve as photographic maps. Accurate measurements can be obtained from them and additional layers can be overlayed for analysis.

California DOQQs are organized in these folders in CaSIL:

• doqq - up-to-date DOQQs

• doqq-archive - archived DOQQs

• index - ESRI Shapefiles that include additional information such as names and availability of new datasets

Further information about DOQQs is in the CEIC catalog under DOQQ Catalog Entry.