用于划分磁异常的新方法—插值切割法

在考察空间域和波数域中划分磁异常区域场和局部场常用方法特点的基础上,作者提出了插值切割法。该方法以当前计算点场值与四点圆周平均值的插值运算为切割算子,通过连续切割,得到磁异常的切割区域场,而从磁异常中减去后,就得到切割局部场。误差分析表明,磁异常中的随机误差在切割区域场中被压制,而在切割局部场中没有明显放大。本研究对四个理论模型和一个野外实例的处理结果表明,这种新方法适合于复杂磁异常区域场与局部场的划分,其他的一些特点是计算速度快、分辨率和精度高。

A NEW INTERPOLATING CUT METHOD FOR IDENTIFYING REGIONAL AND LOCAL FIELDS OF MAGNETIC ANOMALY

On the basis of studying the characteristics of conventional methods foridentifying regional and local fields of magnetic anomaly in spatial and wavenumberdomains,a new method called interpolating cut method is developed.Its cuttingoperator is the interpolation between the present calculated field value and itscircular four-point averaging value.Through successive cutting,the cut regionalcomponent of the magnetic anomaly is obtained,when substracted from themagnetic anomaly,the local component is obtained.The error analysis of theabove process shows that the random error in magnetic anomaly is suppressed inout regional field,and consequently magnified insignificantly in the cut local field.By processing four theoretical models and a field example,it is shown thatthe present method is suitable to complicated magnetic anomaly for identifyingregional and local fields.This method has many advantages,such as great calcula-tion speed,fine resolution and high accuracy.