Orthophotography is the enhanced aerial photography that has been adjusted (rectified) to allow measurements of features within the image. Aerial photos are combined with GIS and terrain data.
Through PAG's Regional Remote Sensing Program, the agency coordinates and manages the production of digital high resolution orthophotography and elevation data sets for its member government entities. Since 1998, the region has used orthos and applied them to transportation planning, preliminary roadway and drainage design, and land use planning efforts.
2015 Order Information
How to View Orthophotos
A digital orthophoto is a computer-generated image of an aerial photograph or aerial digitial image in which displacements caused by camera orientation and terrain have been corrected and projected to a standardized map projection. Digital orthophotos are available in either black and white (gray scale), color (red, green and blue), or multi-spectral (red, green, blue, near infrared).
A Digital Elevation Model (DEM) describes the elevation of points and break lines of the bare earth surface, but does not support contour modeling. A Digital Terrain Model (DTM) describes the elevation of points and break lines of the bare earth surface with additional data to describe ridgelines, peaks and valleys, etc., allowing it to be used for accurate contour modeling.