接收机伪距和相位偏差时变性对PPP的影响分析

Study on the Impact of Temporal Variability of Receiver Code and Phase Biases on PPP

【目的】接收机端偏差包括接收机码偏差和接收机相位偏差,是卫星导航定位的一类显著误差源。传统的定位算法将其视作常量,但事实上该偏差是随时间变化的,如不加以处理,可能会对精密单点定位参数估计产生不利影响。【方法】结合传统精密单点定位模型、顾及接收机端码偏差时变性的精密单点定位模型和星间单差精密单点定位模型,对偏差变化显著的测站进行对比测试,分别比较验后伪距残差、定位误差以及模糊度的估计结果。【结论】结果表明:接收机端伪距偏差存在大幅度变化,而相位偏差的变化较为平稳,因此,接收机端伪距偏差的时变性是影响参数估计的主要因素。对于吸收了该偏差的模糊度参数而言,其估计结果受偏差变化影响显著,对于不吸收该偏差的定位误差而言,其估计结果受偏差变化影响不明显。

[Objective]The receiver bias including receiver code bias and receiver phase bias is a prominent source of error in satellite positioning.It is generally taken as a constant in traditional algorithms.However,bias is time-varying in practical applications.Therefore,it is of great significance to analyze the influence of the time-varying bias.[Methods]Combined with the traditional PPP model,the MPPP model that takes the time variability of the bias into account,and the PPP model with the inter-satellite difference,the stations with significant deviation have been comparatively tested,and the estimation result of posterior residuals of pseudo-range,positioning error and ambiguity have been compared respectively.[Conclusions]The results show that receiver code bias fluctuates substantially,while receiver phase bias fluctuates smoothly.Therefore,the receiver code bias is the main factor affecting parameter estimation.The estimation results of ambiguity that absorb the receiver code bias are significantly affected,while those that does not absorb the receiver code bias are not significantly affected by the time-varying bias.