Flight Results of GPS-Based Attitude Determination for the Canadian CASSIOPE Satellite

Abstract

The paper presents attitude determination results of the “GPS Attitude, Positioning and Profiling Experiment” (GAP) on board the CASSIOPE satellite using real flight data. The GAP payload consists of five minimally-modified commercial-off the-shelf NovAtel OEM4-G2L receivers, which provide dual-frequency GPS measurements and allow for attitude and Orbit determination of the satellite as well as electron density profiling. To the authors’ knowledge, the CASSIOPE mission is the first space mission that provides dual-frequency observations for attitude determination. The data has been analyzed with a GPS attitude determination algorithm originally developed for the analysis of data from the “Flying Laptop” mission. The GPS-based solution for selected attitude maneuvers is compared to a reference orientation provided by the satellite’s star sensors. Furthermore, an analysis of the typical time-to-first-fix (TTFF) of attitude solution is provided. The advantage of dual-frequency ambiguity fixing compared to single-frequency is assessed.