基于移动二次曲面拟合的GNSS点高程异常计算

Research on regional GNSS elevation fitting based on moving quadric surface model

随着全球导航卫星系统(GNSS)高程测量精度和EGM模型精度及分辨率的不断提高,利用少量GNSS水准点进行高程拟合得到待求点的正常高成为可能。根据移去-恢复法思想,利用EGM2008重力场模型计算高程异常长波分量,采用移动曲面模型对残余高程异常值进行拟合。结果表明:在大区域内利用移动曲面之二次曲面法进行残余高程异常值拟合,实测高程异常值与拟合高程异常值较差的中误差小于4 cm,该拟合模型能满足常规的测绘需求。

With the continuous improvement of global navigation satellite system(GNSS)elevation measurement accuracy and the accuracy of resolution of the EGM model,using a smaller number of GNSS benchmarking points for elevation fitting can obtain the normal height of the points.In this paper,the long wave component of elevation anomaly is calculated by using EGM2008 gravity field model according to the removal and restoration method,the residual height anomaly value is fitted by moving quadric surface model.The results show that by using the quadric surface method of moving quadric surface to fit the residual elevation abnormal value in a large area,the measured elevation abnormal value and the fitted elevation abnormal value is less than 4 cm by median.The fitting model can meet the requirements of conventional surveying and mapping production.