Global Positioning System Integer Ambiguity Resolution Without Attitude Knowledge

In this paper, a new motion-based algorithm for global positioning system integer ambiguity resolution is derived. The algorithm represents the global positioning system sightline vectors in the body frame as the sum of two vectors, one depending on the phase measurements and the other on the unknown integers. The vector containing the integer phases is found using a procedure developed to solve for magnetometer biases. In addition to a batch solution, this paper also provides a sequential estimate, so that a suitable stopping condition can be found during the vehicle motion. The new algorithm has several advantages: it does not require an a priori estimate of the vehicle's attitude; it provides an inherent integrity check using a covariance-type expression; and it can sequentially estimate the ambiguities during the vehicle motion. Its only disadvantage is that it requires at least three noncoplanar baselines. The performance of the new algorithm is tested on a dynamic hardware simulator.