Digital Orthoimagery Information

What is digital orthoimagery (DOI)?

Digital orthoimagery or orthophotos combine the image characteristics of a photograph with the geometric qualities of a map. A georeferenced image is processed to remove displacement of objects due to sensor orientation and terrain relief. The resulting orthoimagery will line up with other GIS datasets.

 

Are the orthos for the entire state available at no cost? Are they for sale?

The NY Statewide Digital Orthoimagery Program has covered every portion of the state multiple times since 2000 and the results are available at no cost. Users can use web services or download individual images. A year-by-year summary of areas flown is available. 

 

Why do the color infrared (CIR) orthoimagery colors appear the way they do?

This imagery is acquired with film or sensors which detect the near-infrared wavelengths along with visible light. CIR imagery is created by displaying the recorded near-infrared values as red, with visible red values displayed as green and green values displayed as blue. Objects which reflect more near-infrared energy (such as actively growing vegetation) appear as brighter red in the final orthoimagery. Objects which reflect very little near-infrared energy (such as water) appear much darker.