A New Strategy for GPS Triple-Frequency Long-Baseline Ambiguity Resolution

Abstract

Liu, J.; Zhang, C., and Shu, D., 2020. A new strategy for GPS triple-frequency long-baseline ambiguity resolution. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 189–196. Coconut Creek (Florida), ISSN 0749-0208.Over the last decades, several approaches for GPS phase ambiguity resolution haven been proposed and analysed. For triple-frequency long-baseline relative positioning, the most commonly used approach is LAMBDA, which can resolve all ambiguities in one step. However, the main limitation of LAMBDA is that it is difficult to validate the ambiguity results when it is in high dimension. To address this issue, in this research, a new strategy based on the sequential least squares estimation is proposed and the characteristics of this strategy are analysed. The performance of the new strategy and the commonly used one were assessed and compared using simulated triple-frequency GPS observations. Due to the fact that the two key quantities for the validation of GPS ambiguity are the ratio test and success rate, these two types of values were used to analyse the reliability of the integer ambiguity resolution in this study. The numerical results suggest that the success rates of the two approaches have no significant difference. However, the ratio value of the new approach can be significantly decreased in the case where the ambiguities are correctly fixed. This can smartly improve the reliability of long-baseline relative positioning, and then improve the operational efficiency of coastal surveying.