GPS/BDS接收机端系统偏差稳定性对整周模糊度固定的影响

GNSS接收机端的UPD与接收到的信号频率有关，这导致GPS和BDS系统间的双差模糊度不具有整数特性，为了恢复其整数特性，两系统间的系统偏差需要进行估计或改正。在顾及GPS和BDS之间的时间系统、坐标系统和频率间偏差的基础上，推导出GPS/BDS系统偏差计算模型，并利用不同实验对系统偏差的稳定性进行验证。实验结果表明，不同品牌接收机在GPS/BDS系统偏差方面在一定条件下均具有稳定性；天线类型和天线连接线长度没有对GPS/BDS系统偏差产生显著影响。加入系统偏差改正的GPS/BDS紧组合定位在恶劣环境下表现良好，可将模糊度固定平均所需时间缩短33%，模糊度固定成功率提高31%。

The Stability of GPS/BDS Inter-system Biases at the Receiver End and its Effect on Ambiguity Resolution

Uncalibrated phase delay at the receiver end may depend on the frequency of the signal received, which leads to mixed double difference ambiguity between GPS and BDS and, lost integer character. In order to solve this problem, inter-system biases between GPS and BDS need to be estimated or corrected. Taking the biases of time system, coordinate system and frequency between GPS and BDS into consideration, a computing model of GPS-BDS inter-system bias is deduced, based on which, different experiments verify the stability of inter-system biases. Experimental results show that GPS-BDS inter-system biases of different brand receivers have stability under certain conditions. GPS-BDS inter-system biases are nott influenced by antenna type and antenna cable length significantly. GPS-BDS tight combining with inter-system biases corrected performs well under poor observing condition, and improves the mean time-to-ambiguity-fixing by 33%, and the success rate of ambiguity-fixing by 31%.