高阶重力场模型的高程异常差值改正方法研究

Research on the Correction Method of Elevation Anomaly Difference for High-order Gravity Field Models

通过水准仪测量获取区域高程控制网点正常高的方式,精度高但耗时费力。首先利用EGM2008、EIGEN-6C4、XGM2019e_2159和SGG-UGM-2四种高阶全球重力场模型获取高程异常,再利用少量GNSS水准控制点获取真实高程异常,最后采用平均差值改正短波值方法快速获取高程异常。结合滇中引水工程307个GNSS水准控制点成果,以验证东西方向10 km、20 km、40 km和80 km距离范围内的高程异常改正效果。结果表明,在东西方向40 km内采用4个和2个GNSS水准控制点改正4种模型的高程异常中误差在±5 cm以内,平均中误差改正率接近50%,其中XGM2019e_2159模型整体上更符合似大地水准面。该方法可提高小区域范围内高程异常获取的精度和效率。

The previous regional grade elevation control network was measured by level to obtain the normal height of elevation control points,which is highly accurate but time-consuming and laborious.We used EGM2008,EIGEN-6C4,XGM2019e_2159 and SGG-UGM-2 four high-order global gravity field models to obtain the elevation anomaly at first.And then,we used a few GNSS level control points to obtain the real elevation anomaly.Finally,we proposed a method of correcting short wave value by mean difference to obtain the elevation anomaly quickly.We verified the correction effect of elevation anomalies in the distance range of 10 km,20 km,40 km and 80 km in the east-west direction respectively.The results show that the average error correction rate is nearly 50%,and the XGM2019e_2159 model is more consistent with the quasigeoid in the whole.This method can improve the accuracy and efficiency of elevation anomaly acquisition in a small area.