Helicopter Survey Methods for Mapping

摘要

This 1948 interim report covers an investigation and field tests conducted to determine the feasibility of using a helicopter to serve as a visible signal for triangulation and trigonometric leveling in establishing secondary control for mapping in difficult terrain. The purpose is to develop and test a method for establishing secondary control points for topographic mapping in which a helicopter is used as a signal for horizontal and vertical direction observations from ground stations of known position and elevation. The minimum accuracies acceptable are 1 part in 2,000 in horizontal position and plus or minus 5 feet in elevation.