重力异常阶方差模型精度及其截断误差分析

在评估重力场模型计算空间扰动引力精度时,对模型截断误差常采用阶方差方法。文中将6种经典的重力异常阶方差模型与现有超高阶重力场模型的阶方差进行比较,TSD模型与重力场模型的差值最小。根据重力异常阶方差模型TSD,文中分析不同高度、不同阶次利用重力场模型计算空中扰动引力时截断误差的影响。实验结果表明:36阶模型截断误差最大径向和水平方向分别为26.455 1mGal、25.946 3mGal;360阶模型截断误差最大径向和水平方向分别为9.969 0mGal、9.960 9 mGal;2160阶模型截断误差最大径向和水平方向分别为2.538 5 mGal、2.538 1mGal;2160阶模型计算空中扰动引力时,即使在低空附近,截断误差在2.5mGal以内,计算高度超过5km,截断误差可以忽略;超过400km的高度,都可以用36阶模型计算,截断误差在1mGal以内。

Analysis of degree variance of the gravity anomaly model precision and its truncation error

When the precision of the gravity field disturbance is analyzed ,the truncation error is the main factor w hich should be considered.Six classical degree variance of the gravity anomaly models are compared with the existing high‐order earth gravity model .The difference between the TSD model and the earth gravity model is the smallest .According to the TSD ,the influence of truncation error is analyzed when gravity field model is used to calculate the gravity of air disturbance .When using the 2160 order model to calculate the gravity of the air disturbance ,even in the vicinity of the low altitude ,the truncation error is within the 2.5 mGal ;and w hen the height of the computation is over 5 km ,the truncation error can be ignored ;when the height of the computation is over 400 km ,it can be calculated with the 36 order model and the truncation error is within 1 mGal .