Precision Directly Georeferenced Unmanned Aerial Remote Sensing System: Performance Evaluation

This paper presents a practical evaluation of a direct georeferencing implementation with a quantitative analysis of the error budget of the georeferencing solution with respect to an Unmanned Aerial Remote Sensing System (UARSS). Direct georeferencing of remote sensing data using on-board navigation sensors is a critical step toward making near real-time remote sensing possible. By eliminating the need for costly and time-consuming ground control points, direct georeferencing provides the ability to fly over areas that do not have to be surveyed beforehand. This can decrease the resources required to produce usable remote sensing data by orders of magnitude. Particularly suitable are natural resource, agricultural, and infrastructure monitoring applications, where rapid and repeatable acquisition of the data directly into a Geographic Information System would be advantageous.A serious limitation of these systems is providing sufficient accuracy using low-cost and low-weight navigation sensors. This paper discusses a program for assessing the accuracy of the navigational sensors, as well as the results of a real-world implementation. A benchmarking platform for comparing the UARSS sensors to high-accuracy sensors is used for a ground-based test. Misclosures evaluated for determining the overall accuracy of the direct georeferencing system. The components of the error budget are presented, with an analysis of those elements relevant to the scope of this paper. Methods are presented for evaluating these additional components. The design goal of one meter ground accuracy is not met, and a forward-looking plan is presented for improving the performance of the system.