A GPS Based Attitude Determination System for a UAV Aided by Low Grade Angular Rate Gyros

The Satellite Navigation and Positioning (SNAP) group at The University of New South Wales has been conducting research into high precision attitude determination using a multi-antenna single-frequency GPS array, aided by low grade angular rate gyros. The objective of the research is to develop an accurate, reliable attitude sensor solution at an affordable cost which can be implemented on UAVs (Unmanned Airborne Vehicles) developed for geophysical exploration by Newmont Australia. UAVs used by the geophysical exploration industry will be required to fly lower and for significantly longer periods compared to UAVs used for most other applications. Flying at a low height, approximately 30m above ground level, introduces many communications and control challenges, not the least being the need for rapid response to unexpected platform movements. The GPS attitude determination subsystem is important in enabling an external, independent reference to constrain the control inputs to the UAV flight subsystem. Of particular importance is a good understanding of the integrity of the system.