广义残差地形模型及其在局部重力场逼近中的应用

Generalized Residual Terrain Model and Its Application in Regional Gravity Field Approximation

研究了残差地形模型中的非调和性问题,比较了基于棱柱体和球冠体的积分模型,提出了基于球冠体积分的广义残差地形模型。以泊松小波径向基函数为构造基函数,结合广义残差地形模型,融合多源实测重力数据构建了局部区域重力场模型。研究结果表明:基于棱柱体积分的残差地形模型精度较低,在山区可能引入毫伽级以上的误差,建议采用更为接近真实地形表面的球冠体积分模型。相比于原始的残差地形模型,基于球冠体积分的广义残差地形模型能更为精确地逼近局部重力场模型中地形因素引起的高频效应。

We studied the so-called non-harmonic problem in residual terrain model（RTM）and compared the RTM corrections based on prisms and tesseroids.Moreover,we proposed the generalized RTM based on tesseroids,together with which the regional gravity field was modeled based on Poisson wavelets basis function by using heterogeneous gravity data sets.The results show that the RTM correction based on prism integral has a poor performance in mountainous regions,which may introduce errors with the magnitude of several mGal.Thus,we suggest using RTM based on tesseroids,which lead to a better approximation of the topography.Compared to original residual terrain model,the generalized one leads a better approximation of the regional gravity filed at the high-frequency part caused by local topographical variation.