GNSS形变监测静态基线网中多基线联合解算两步法

Two-Step Method of GNSS Static Baseline Network Solution for Deformation Monitoring

GNSS(global navigation satellite system)静态基线网的解算方法通常采用单基线解算模式或多基线解算模式。这两种方法均有一定的局限性。本文综合两类方法的优点,提出了单基线和多基线联合解算模式的两步法。首先基于单基线模式利用多频率的载波相位观测值解算监测站间的双差整周模糊度,并使用严格的固定准则确定模糊度;然后利用多基线模式进行联合坐标和天顶对流层参数的估计,再结合最小二乘估计解算定位结果。选取国内某水电站静态形变监测数据为研究对象,进行基线解算方法测试和分析。实验结果表明多基线联合解算两步法在精度和可靠性上有较大优势,平面定位精度为亚毫米级,高程定位精度提高1~2倍;并可以明显改善基线网的解算速度,在高精度变形监测应用中具有可行性与通用性。

The solution method of GNSS static baseline network usually adopts single baseline solution mode or multi baseline solution mode.Both methods have certain limitations.Based on the advantages of the two methods,a two-step method of single baseline and multi baseline joint solution mode is proposed in this paper.Firstly,based on the single baseline mode,the double difference integer ambiguity between monitoring stations is solved by using the carrier phase observations of multiple fre⁃quencies,and the ambiguity is determined by strict fixed criteria;Then,the multi baseline model is used to estimate the joint coordinates and zenith tropospheric parameters,and then com⁃bined with the least square estimation to solve the positioning results.The static deformation monitoring data of a hydropower station is selected as the research object to test and analyze the baseline solution method.The experimental results show that the two-step method of multi baseline joint solution has great ad⁃vantages in accuracy and reliability.The plane positioning ac⁃curacy is sub millimeter level,and the elevation positioning ac⁃curacy is improved by 1~2 times;It can obviously improve the calculation speed of baseline network,and has feasibility and universality in the application of high-precision deformation monitoring.