Aerial Profiling of Terrain System

Abstract

Since 1974, the U.S. Geological Survey (USGS) has been developing the Aerial Profiling of Terrain System (APTS) for measuring stream‐valley cross sections and profiles, older map reliability testing, and producing control for topographic maps. The system, which has completed laboratory testing at the Charles Stark Draper Laboratory in Cambridge, Mass., consists of an inertial measuring unit (IMU), a laser tracker, a laser profiler, a video imaging system, supporting electronics, and a computer. The equipment has been installed in a modified Twin‐Otter aircraft based at Hanscom Field, Mass.