顾及残差约束的多面函数法融合卫星测高和船载重力

An improved multi-surface function method with residual constraint for the fusion of shipborne and satellite altimetry derived gravity data

融合多源重力数据是精化局部区域重力场的必要手段。本文通过引入残差约束因子,改进了基于多面函数的多源海洋重力数据解析融合方法。以日本群岛附近海域为例,使用卫星测高反演重力场模型和船载重力数据,分析了分块大小、融合船载重力数据量及其分布对该方法的影响,并与改进前多面函数法及最小二乘配置法的结果进行比较,验证了改进方法的可靠性和有效性。与验证船载重力数据相比,顾及残差约束的多面函数法精度最好,极值和标准差均显著下降。与多面函数法相比,不仅较好地改善了控制船载测点附近的不符值,而且将其较好地推估至整个区域的船载观测数据之间,残差分布合理,且无明显测线状误差。

In order to obtain accurate regional gravity field,it is necessary to fuse multi-source gravity data.In this study,an improved analytical fusion method based on multi-surface functions by introducing residual constraint factors is proposed.Taken the surrounding the Japanese archipelago area as example,collecting the shipborne gravity data and satellite altimetry derived gravity field model,several factors which affect the accuracy of fusion results,including the block size,the quantity and distribution of the fused shipborne gravity data,are analyzed.And with optimal above factors,the fused results of the improved method are compared with those of the least square collocation method and the multi-surface function method.Compared to the shipborne gravity data for verification,the improved method with residual constraint has the best accuracy,as well as the smallest extreme values and standard deviations.Furthermore,the improved method reduced the discrepancy of two kinds of data near the control shipborne measuring points,and extrapolate to the other areas to improve the accuracy of satellite altimetry derived gravity model with reasonable distributed residuals.