湖北重力网基准点选取最优策略分析OA

Based on the gravity observation data from the Hubei gravity network in 2019,we study the impact of datum points selection on the adjustment accuracy of gravity network from three aspects:the spatial distribution of datum points,the number of datum points,and the maximum gravity seg-ment difference of selected datum points using the classical adjustment method,and obtain the opti-mal scheme for datum points selection in Hubei gravity network.Additionally,we conduct a forward simulation using priori mean error to evaluate the adjustment effects controlled by different datum points,and explore the optimal selection schemes for single-datum,dual-datum,triple-datum,and quadruple-datum configurations.The results show that:1)The selection of datum points should pri-oritize their spatial distribution to maximize the control effect of each datum point.The number of da-tum points should be considered next,after a certain number is reached,the adjustment accuracy of gravity network will tend to saturate.Finally,the maximum gravity segment difference of selected da-tum points should be considered,with preference given to datum points with larger segment differ-ence.2)For the Hubei gravity network with fixed gravity datums,the average adjustment accuracy improvement rates from optimal single-datum point to optimal quintuple-datum points are 16.81％,8.31％,4.84％,and 2.98％,respectively.After statistical and simulation analysis,it is suggested that Hubei gravity network use four datum points of Wanzhou,Zigui,Xiangyang,and Wuhan.3)Using priori mean error to simulate the selection of optimal datum points,the optimal single-datum point is Jingmen,the optimal dual-datum points are Fengjie and Wuhan,the optimal triple-datum points are Wanzhou,Buzhuanghe,and Wuhan,and the optimal quadruple-datum points are Wanzhou,Shiyan,Buzhuanghe,and Wuhan.Compared with the optimal datum points obtained from the actual data analysis,the simulated optimal datum points have a more rational spatial distribution and a slight im-provement in adjustment accuracy.The priori mean error method used in this article to simulate the optimal datum points of gravity network has certain reference value for datum points optimization of the existing national network,regional network,or the planning gravity measurements.