A modified attitude domain search method for GNSS attitude determination

The efficiency of conventional attitude domain search is low, and its real-time performance highly depends on the angular constraint. In this paper, given a constant baseline length constraint, we proposed a modified attitude domain search method to resolve integer ambiguity. First, we rewritten the least-squares (LS) objective function to get an rigorous LS attitude domain search model. Second, we used rounding to modify this attitude domain search model, and then derived an orthogonal-diagonal decomposition method and the corresponding attitude search step-lengths to simplify the search procedure. All the ambiguity candidates are determined by traversal search in the attitude search space. Finally, the LS objective function is used to fix the integer ambiguities. As the results of tests, our new method has high success rate and good real-time performance, and shows its potential in high dimensional ambiguity resolution. Because of its good performance, our new method may be considered in real-time GNSS attitude determination.