利用高精度GNSS水准及垂线偏差数据分析重力场模型的误差特性

Analysis of error characteristics of earth gravity model using high-precision GNSS/leveling and deflection of the vertical data

高精度的GNSS水准及垂线偏差等数据对全面评定重力场模型精度具有重要意义.本文利用美国GSVS2011、GSVS2014项目高精度的GNSS水准及垂线偏差等数据,通过谱组合方法分析了DIR-R5、GOCO05S和TIM-R5等具有代表性的重力场模型的可靠阶次,并分别与EIGEN-6C4形成组合模型DIR-R5-Com、GOCO05S-Com、TIM-R5-Com,在此基础上,进而分析了EGM2008、EIGEN-6C4与3个组合模型的误差特性.实验结果表明:(1)DIR-R5、GOCO05S和TIM-R5模型截断至220阶以前是可靠的;(2)整体上,重力场模型沿经圈走向(GSVS2011)的高程异常和垂线偏差精度要优于沿纬圈走向(GSVS2014)的精度;(3)重力场模型垂线偏差卯酉圈分量的精度要优于子午圈分量的精度;(4)模型高程异常在经圈上的相对精度整体上要优于在纬圈上的精度.

The high-precision GNSS/leveling and deflection of the vertical are of great significance for evaluating the accuracy of gravity field model. In this paper, the high-precision GNSS/leveling and deflection of the vertical data of the US GSVS2011 and GSVS2014 projects are used to analyze the reliable order of representative gravity field models such as DIR-R5, GOCO05S and TIM-R5 by spectral combination method, and respectively combined with EIGEN-6C4 to form combined models, such as DIR-R5-Com, GOCO05S-Com and TIM-R5-Com. The error characteristics of EGM2008, EIGEN-6C4 and three combined models are analyzed. The experimental results show that the DIR-R5, GOCO05S and TIM-R5 models up to degree and order 220 are reliable. Overall, the accuracy of height anomaly and deflection of the vertical from the gravity field model on the meridian is higher than that on the latitudes. For the deflection of the vertical of the model, the precision of the prime vertical component is higher than that of the meridian component. The relative precision of the model height anomaly on the meridian is higher than that on the latitudes.