优选延拓技术及其在中国布格重力异常图处理上的应用  

PREFERENTIAL CONTINUATION AND ITS APPLICATION TO BOUGUER GRAVITY ANOMALY IN CHINA

作　　者：许德树[1] 曾华霖[2] 

机构地区：[1]中国地质科学院地球物理地球化学勘查研究所,廊坊065000 [2]中国地质大学工程技术学院,北京100083

出　　处：《现代地质》2000年第2期215-222,共8页Geoscience

基　　金：国家海洋 86 3计划青年基金资助项目 !(编号 :82 0- Q- 0 7)

摘　　要：从维纳滤波原理出发 ,应用多层格林等效层模型精确模拟实测重磁场的径向对数功率谱 ,实现了重磁场在频率域的优选延拓。通过理论模型实验 ,证实了优选延拓算子具有向上延拓时不过分衰减低频信号、向下延拓时不过分突出或压制高频信号的选择性功能。根据优选向上延拓可以保证低频成分不衰减的性质 ,能够较为精确地提取区域异常 ,进而分离出局部异常。利用优选向下延拓可以对指定波段放大 ,而对其他波段保持全通的特征可以实现对某一深度或尺度的局部异常有选择地增强。运用优选延拓技术对中国大陆布格重力异常进行了增强与分离处理 ,获得了基于最佳滤波原理计算的中国大陆区域重力异常、剩余重力异常和带通重力异常。为研究中国大陆表层的岩石物性结构及平面分布特征提供了新的资料 。Gravity field can be preferentially continuated,with the log power spectrum of measured potential field being accurately simulated by some Green′s equivalent layer models based on the Wiener filter theory.The preferential continuation operator has been proved that it has these advantages:when it is used for upward continuation,the low frequent signal does not be attenuated excessively;when is used for downward continuation,the high frequent signal does not be magnified and inhibited considerably.While in conventional methods both high and low frequent signals are attenuated simultaneously for upward continuation and the low frequent signal is magnified and the high frequent signal is truncated for downward continuation.The preferential continuation breaks up the restrictions of the conventional continuation.So the preferential continuation is a method that has the ability to self adaptive qualitatively enhance and separate the potential field anomalies.In this paper,the Bouguer anomaly in the mainland of China is processed using the preferential continuation.And the preferential downward continuation and residual gravitational anomalies in the mainland of China that is calculated based on the optimum filter principle are acquired.

关 键 词：优选延拓 中国布格重力异常图 重磁测量 

分 类 号：P631.1[天文地球—地质矿产勘探]