基于北斗三频的实时变形监测数据处理

Real-Time Deformation Monitoring Data Processing Based on BDS Triple-frequency Observations

针对观测条件较差时,基于双频观测值的传统变形监测数据处理算法无法快速、可靠地固定原始频点模糊度的局限性,分析了GPS和北斗导航系统BDS不同解算模式下的单历元模糊度固定成功率,提出了基于北斗三频观测值的变形监测数据处理算法。该算法采用三频模糊度解算(three-carrier ambiguity resolution,TCAR)逐次固定超宽巷、宽巷、原始频点模糊度;在不能可靠固定原始频点模糊度时,通过观测值域恒星日滤波削弱宽巷多路径的影响,采用模糊度固定宽巷进行坐标解算。利用实测数据进行检验后的试算结果表明:TCAR单历元模糊度固定成功率较双频模式有了较大提高,但在观测条件较差时难以保证较高的成功率;而宽巷模糊度固定可达到100%的成功率;经观测值域恒星日滤波后宽巷固定解坐标水平方向均方根(root mean square,RMS)可达到7mm。

In real-time deformation monitoring applications,ambiguity cannot be quickly and reliably resolved under poor conditions using dual-frequency observations.In this paper,we analyze the single epoch ambiguity resolution success rate of GPS and BDS system under different calculating models.A new method based on triple-frequency BDS observations is proposed to fix the original ambiguity based on the TCAR（three-carrier ambiguity resolution.Sidereal day filtering based on observing domain reduces multipath errors in wide-lane observations under conditions where the original ambiguity cannot be fixed reliably.Real data is used to test the method,results show that the success rate and accuracy are improved in comparision to the dual-frequency models.A success rate of 100% was achieved using the wide-lane ambiguity resolution,and the RMS values for the wide-lane fixed solution reached 7mm after filtering.