A Gaussian sum filtering approach for phase ambiguity resolution in GPS attitude determination

The problem of phase ambiguity resolution and filtering for interferometric GPS attitude determination is considered. Traditionally, the resolution of the phase ambiguity and the filtering stages were performed separately with the filter formulated on the basis that the phase ambiguity is correctly resolved. Should the pre-processing stage not resolve the ambiguity correctly, erroneous results may occur. In response, a unified solution is proposed in which the ambiguity resolution and filtering processes are combined under a Gaussian Sum Filtering (GSF) framework. The GSF naturally accounts for the measurement ambiguity by generating multi-modal probability densities, which leads to a probabilistic interpretation of the attitude estimates. Simulations are performed to illustrate the effectiveness and functionality of the proposed solution.