Improved attitude determination technique of GNSS based on baseline constraint and recursive multiple-epoch

In the technology of the global navigation satellite system(GNSS) single frequency attitude determination, the single-differenced carrier phase and code phase combination model and the CLAMBDA method were used to estimate the integer ambiguities. In this way, the success rate of GNSS attitude determination can be improved to a certain extent, but there is still room for improvement. In order to solve this problem, a multiple-baseline triangular constraint recursive multiple-epoch method was presented for improving the success rate of attitude determination farther. Triangular constraint is mainly for the secondary baseline, and can be used to make the integer ambiguity resolution more accurately. The recursive multiple-epoch ensures that the attitude angle can still be calculated when the integer ambiguity of this moment is unknown. It can be used for not only the main baseline but also the secondary baseline. The testing results show that the proposed method can improve the success rate of attitude determination for the secondary baseline to more than 99.7%.