附加对流层约束的大高差区域短时GNSS网解及其性能

Short-term GNSS network solution and performance in large height difference region with tropospheric delay constraint

大落差高山区域GNSS监测严重受制于对流层延迟影响,导致定位精度降低。本文提出附加地面点对流层延迟先验信息约束方法,实现短时同步双差观测高精度解算。该方法能充分利用远距离地面站网的增强信息,显著减少高山区域监测的观测时长,增大站间距离,降低山区测量任务的作业成本。本文从观测时长、基线距离时空特性及基站数量3方面进行适用性试验验证,试验结果表明,以地面站点长期GNSS观测获得的高精度对流层延迟作为约束,可有效削弱大落差引起的残余对流层延迟的影响,提高整周模糊度固定率,实现山顶监测点的快速高精度定位和对流层延迟参数估计;与非约束法相比,对流层先验约束后各坐标分量精度均有所提高,高程方向精度提高明显。

The observation of GNSS monitoring in mountain area is often severely restricted by tropospheric delay,resulting in the reduction of positioning accuracy.In this paper,a constraint method for the prior information of tropospheric delay at ground points is put forward to realize the fast and high-precision double differenced observation of the peak.This method can make full use of the augmentation information of tropospheric delay of long-distance ground station,the observation duration decreased notably,increase the stations range of mountain monitoring,so as to reduce costs of mountain measurement task.In this paper,the applicability is verified by the spatio-temporal characteristics of observation duration,baseline distance and number of ground stations.The experimental results indicate that takes the high-precision tropospheric delay into account as prior constraints,acquired by long-time GNSS observation at ground stations,which can weaken the influence of tropospheric delay residuals efficiently induced by large heights different between different stations and improve success rate of ambiguity fixing,and can achieve tropospheric delay parameter estimation and fast high-precision positioning of peak monitoring points.Compared with the unconstrained method,the accuracy of each coordinate component is improved after the troposphere prior constraints,and the accuracy of the elevation direction is improved significantly.