The Methods and Analysis of Zero Baseline and Ultra-Short Baseline Ambiguity Resolution Based on BDS Observations

Integer ambiguity resolution is one of the difficult and important points in precision relative positioning. As we all know, LAMBDA (Least-squares AMBiguity Decorrelation Adjustment) method can be regard as the most rigorous algorithm in ambiguity resolution methods, it is still effective in the ambiguity resolution of triple-frequency GNSS precision positioning. So, the algorithms such as LAMBDA, Rounding, and Bootstrapping are adopted in this paper to solve the zero baseline and ultra-short baseline BDS observations, respectively, and the results of ambiguities resolution for pseudorange and carrier-phase double difference observations and increments of ENU direction for baselines are obtained, which the C01 satellite is taken as reference satellite in the whole baselines resolution. Through comparing the consequences of ambiguity resolution and the difference for increment of ENU direction between the three methods and TBC (Trimble Business Center) software, results show that performance of the three methods is at the same level, therefore both of them can be used for ambiguity resolution of zero baseline and ultra-short baseline.