GPS-based single-epoch attitude determination without prior knowledge of measurement precision

During attitude determination using the Global Positioning System (GPS), incomplete knowledge of the stochastic model of the observables often occurs in realistic applications, resulting in the failure of the traditional least-squares method for the Global Navigation Satellite System baseline model. This paper presents a single-frequency single-epoch GPS attitude determination method, which is aimed at attitude determination without theprior knowledge of measurement precision. The new approach is a combination of an analytical resolution and the constrained integer least-squares theory. By using the global minimizer of the fixed ambiguity objective function, our method identifies the most likely solution from all possible analytical candidates. Simulation experiments demonstrate the performance of the proposed algorithm for different noise levels and different baseline lengths. To determine the applicable scope of this scheme, the success rate gap of the least-squares method is also analyzed. Actual experiments also verify the effectiveness of theproposed method.