US 60 Airborne GPS, Arizona Department
of Transportation/HDR Engineering

Sixty-five horizontal GPS points were surveyed to control a 20-linear-mile Airborne GPS project. Two-foot contour mapping was provided based on U.S.G.S. 83 horizontal control datum. Sixty-two photo centers were calculated for 31 stereomodels. Results were calculated through post processing of three Ashtech Z-12 GPS receivers. One used in the airplane collecting photo center data and two ground base units. Only one base unit is required to obtain required results; however, PEC uses two base units to insure quality through cross checking and redundancy.