一种基于星间单差模糊度固定的载波伪距生成方法

Generating Carrier Range with Between-satellite Single-difference Phase Ambiguity Resolution

随着测站和卫星数量的不断增加,大规模GNSS网的数据处理面临越来越大的挑战。将载波相位观测量转化为载波伪距是提高大规模GNSS网数据处理效率的有效方法。本文提出在精密单点定位基础上进行星间单差模糊度固定生成载波伪距的方法。采用中国大陆构造环境监测网络(陆态网)观测数据进行了验证。结果表明,对于包含252个测站的观测网,采用载波伪距进行整网解的处理时间不超过20min。剔除异常测站后,240个陆态网测站的月坐标重复精度在N、E和U方向的均值分别为0.74、0.85和2.53mm,略优于原始数据整网解的结果。本文还探讨了采用原始数据和载波伪距进行整网解的关系,利用带约束条件的观测模型对不同方法生成的载波伪距应用于整网解的原理进行统一解释,并指出了载波伪距整网解与原始数据整网解的理论等效性。

Data processing for large-scale GNSS network is faced with increasing challenges as both the number of tracking stations and navigation satellites continuously increases.It has been shown that converting original carrier phase observations to carrier range observations is one of the valid approaches to improve the computing efficiency of data processing.In this paper,a new method to generate the carrier range observation is presented,correcting the ionosphere-free combination of carrier phase using the estimation of un-difference ambiguities obtained in the PPP solution with fixing between-satellite single difference ambiguities.Experiments with GPS data from the crustal movement observation network of China(CMONOC)during day1-30of year2017are conducted to validate the proposed approach.It is demonstrated that,using the carrier range observation,the computation time for the network with252stations is less than20minutes.If the original phase observations are used,it takes about11hours,nearly half of which is spent for resolving integer double difference ambiguities.Excluding the12abnormal stations,the monthly coordinate repeatability of the240stations are0.74,0.85and2.53mm on average respectively in the directions of N,E and U,which are slightly better than those with original phase data.We also discuss the difference of integrated network solutions with original phase and carrier range.Using the concept of adjustment model with constrain condition,a unified formula of observation model is presented to interpret the principle of integrated network solution with carrier range generated with various integer ambiguity resolution strategies,i.e.resolving zero-difference,double-difference and between-satellite single-difference integer ambiguities.It is concluded that the effect of network solution with carrier range observation is theoretically equivalent with the traditional approach with original phase data.