滤波因子V_(zz)在重力资料褶积处理中的应用

An Application of Filtering Factor V_(zz) to Convolution Processing of Gravity Information

重力异常的振幅谱是主频为零并随频率的增大而呈指数衰减的曲线。为了获得反映局部构造的高、中频成份,选用具有带通滤波特性的重力位二阶导数作滤波因子对重力异常进行滤波,用比较法、切线法和对数谱法反演界面的埋藏深度,该方法具有降低区域背景对重力测量值的影响、突出微弱局部异常的作用。通过理论模型和珠江口某工区实际资料计算验证,所求界面埋深精度有明显提高。

The spectral of gravity anomaly is a curve in which the main frequency is zero and appears an exponential decay with frequency enlarging, in order to obtain the high and middle frequency components which may show local structure, the gravity potential second derivative which has the characteristics of band pass filtering is adopted to filter the gravity anomaly. The surface depth inverse is performed using the comprative method, the tangent method and the logarithmic spectral method. These methods lay stress on weak local anomaly and may reduce the influence of the areal background on the anomaly value. Theoretical model and actual data calculations performed at a spot in Zhujiangkou area reveal the precision of the surface depth acquired with these methods.