Single antenna GPS carrier amplitude based rolling angle determination

Traditional methods of determining roll rate and roll angle are expensive, and could be justified only for high value vehicles. For cost-effectiveness, GPS-based measurements are preferred for determining roll angle of spinning vehicles. GPS carrier amplitude measurements are the two main techniques used for attitude determination. In this paper, for determining roll angle of a spinning vehicle, the I/Q amplitude characteristics of GPS signals received at a single antenna are measured using the signals output directly by a hardware correlator that is driven at the satellite tracking frequency used for navigation solution. The roll angle are determined by a Roll angle filter, which is preferably an EKF, whose inputs include the measured I/Q characteristics and the navigation solution. The actual experiment results for roll rate and roll angle obtained for a spinning vehicle using only I/Q amplitude information, the performance of proposed method provides accuracy that is good enough for most applications.