高精度海洋重力异常格网插值技术研究

The study of high precision interpolation technology in marine gravity anomaly

通过对当前常用的Kriging方法、改进的二次曲面Shepard方法(MQS)、径向基函数法(RBF)三种格网插值方法进行实验比较和分析,可以得出如下结论:MQS方法插值速度快,整体精度高;RBF插值内部区域精度很高,但是容易在边缘区域出现异常误差,而且计算速度较慢;而Kriging方法在速度上略高于RBF,但精度上要稍低于RBF和MQS。另外,基于插值误差与测区重力异常具有很强相关性的特点及RBF插值方法产生的误差特性,提出了利用光滑因子和边缘数据延拓分别对MQS和RBF方法进行改进的设想,并通过实验进行了验证。

Three usual interpolation methods such as Kriging, modified quadratic shepard （MQS） and radial basis function （RBF） are compared and analyzed in marine gravity anomaly. It shows that the MQS method is the fastest and most accurate, and the RBF method is also good in precision except some abnonnity on the edge area, but the calculation speed is the slowest. The Kriging method is not so good in precision as the other two, but faster than the RBF. In addition, two modified ideas to the MQS and RBF are brought out based on the characteristic that the interpolation error has large pertinency with the gravity anomaly and RBF errors just appear in the edge area. Test result shows that the modified methods are effective.