Global Positioning System Integer Ambiguity Resolution Without Attitude Knowledge

Abstract

Inthispaper,anewmotion-basedalgorithmforglobalpositioningsystemintegerambiguityresolutionisderived. Thealgorithmrepresentstheglobalpositioningsystem sightlinevectorsinthebodyframeasthesumoftwovectors, onedependingonthephasemeasurementsandtheotherontheunknownintegers.Thevectorcontainingtheinteger 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 newalgorithm has several advantages: it doesnot requirean a prioriestimateofthevehicle’ s attitude; it provides an inherent integrity check using a covariance-type expression; and it can sequentially estimate the ambiguitiesduring thevehiclemotion. Itsonly disadvantageisthatit requiresatleastthreenoncoplanar baselines. The performance of the new algorithm is tested on a dynamic hardware simulator.