Airborne remote sensing without ground control

Abstract

Describes how position and orientation measurement systems are used to directly georeference airborne imagery data, and presents the accuracies that are attainable for the final mapping products. The Applanix Position and Orientation System for Airborne Vehicles (POS/AV™) has been used successfully since 1994 to georeference airborne data collected from multispectral and hyperspectral scanners, LIDARs, and film and digital cameras. The POS/AV™ uses integrated inertial/GPS technology to directly compute the position and orientation of the airborne sensor with respect to the local mapping frame. A description of the POS/AV™ system is given, along with an overview of the integrated inertial/GPS processing. An error analysis for the airborne direct georeferencing technique is then presented. Firstly, theoretical analysis is used to determine the attainable positioning accuracy of ground objects using only camera position, attitude, and image data, without ground control. Besides theoretical error analysis, a practical error analysis was done to present actual results using only the POS data plus digital imagery without ground control except for QA/QC. The results show that the use of POS/AV™ enables a variety of mapping products to be generated from airborne navigation and imagery data without the use of ground control.