Evaluate and develop high-performance GPS navigation using free GPS software

Abstract

Synthetic Aperture Radar (SAR) mounted on an aircraft allows us to create images of landscapes. In order to obtain such high resolution images it is crucial to accurately determine the flight-path of the instrument's platform. For centimeter-level accurate positioning of the aircraft, a differential positioning technique based on Global Navigation Satellite Systems (GNSS) is used. This method, also known as Real-Time Kinematic (RTK) positioning, utilizes carrier phase signals and relies on a second (fixed) "base station" with well known coordinates. In this thesis the accuracy of the open-source GNSS library RTKLIB was evaluated. A comparison with results from a commercial software has shown that RTKLIB is able to provide similar positioning performance. In general it could be concluded that the accuracy of RTKLIB is sufficient for the given SAR application. Moreover, a batch-driven processing chain utilizing RTKLIB was realized in order to minimize manual interactions. The thesis was conducted at Saab AB.