ANALYSIS OF AMBIGUITY RESOLUTION METHODS FOR ATTITUDE DETERMINATION USING GPS CARRIER PHASE MEASUREMENTS

A body orientation can be calculated if GPS measurements are collected simultaneously from three or more GPS antennas body-mounted properly. Carrier phase double differences are used as GPS measurements and the ambiguous integer number of cycles in such measurements must be determined. For algorithm speedup constraints steaming from the fixed antennas configuration geometry are imposed. Two algorithms were analyzed accomplishing real-time attitude determination. Euler angles and quaternion formulation were compared. The test baselines were separated 1 meter apart perpendicularly. The results showed that the accuracy of both methods is in the order of 0.1 degrees to 0.2 degrees or better, but CPU times are quite different.