Application of Differential Global Positioning System (DGPS) Indexing to Remote Sensing Photogrammetry

摘要

In photogrammetry, radial displacement occurs when the point being imaged is not at the elevation of the mean datum. It is standard practice in photogrammetric mapping to provide 60% forward overlap and 30% sidelap between adjacent photographs. Such overlap is often required as the aircraft is subject to altitude variations, tip, and tilt as the flight proceeds. Differential GPS is used to minimize 3-D positional variations and provide precise indexing of the photographic exposures. This paper reports on the application of differential GPS to scientifically map the “uplight” emanating from the Ames, IA area, which serves to provide preliminary photogrammetry for Iowa State University engineering students working on Aerial Integrated Platform (AIP) senior projects. The data and it’s acquisition technique also serves as a model for low cost mapping of non-downward municipal and business lighting practices contributing to light pollution.