时变重力场的非各向同性高斯滤波比较

使用GRACE反演地球表层的质量异常,其结果取决于构造的平滑函数即滤波方法。本文阐述了两种在经典高斯滤波基础上构造的Fan滤波和Non-isotropic Gaussian(Non)滤波,两者均对GRACE的阶和次起作用。在同一阶下,两者的权重随着次数的升高而衰减,但衰减的趋势不同,比如在20阶时,Fan滤波呈抛物线变化,而Non滤波则为线性衰减;在40和60阶,两者均呈抛物线变化。使用CSR发布的GRACE Level-2 RL05数据反演地表质量异常,两者的结果相近。

On the Comparison of Non-Isotropic Gaussian Filtering Methods for Time-Variable Gravity Filed

The Earth surface mass anomalies derived from GRACE depends on the smoothing kernels , i.e., filtering methods .In this paper, we review two filtering approaches based on classical isotropic Gaussian filter , Fan filter and Non -isotropic Gaussian filter, which both reduce the weight of degree and order .In the same degree , Fan filter and Non-isotropic Gaussian filter show different changes trend, e.g., in degree 20, the former presents parabolic path while the latter shows linear variations .Using the GRACE Lev-el-2 RL05 data released by CSR to estimate the mass anomalies , the results of Fan filter and Non -Gaussian filter are very close .