基于位场分离与延拓的视密度反演  

The inversion of apparent density based On the separation and continuation of potential field

作　　者：徐世浙[1] 余海龙[1] 李海侠[1] 田钢[1] 杨金玉[1] 

机构地区：[1]浙江大学理学院地球科学系,杭州310027

出　　处：《地球物理学报》2009年第6期1592-1598,共7页Chinese Journal of Geophysics

基　　金：国家863计划(2006AA062107);国家自然科学基金项目(40774059);浙江省科技厅院士基金资助

摘　　要：由于目前计算机内存和速度的限制,在对大面积重力资料进行三维密度反演时,已有的反演方法很难奏效.文中提出了一种基于位场分离与延拓的视密度快速反演方法:首先应用场分离的切割法对平面上的重力场进行不同深度层源的切割分离;然后运用大深度向下延拓方法将各层的场延拓至相应的深度;最后反演出各深度层的密度.反演得到的密度是各深度层密度的近似分布,称为视密度反演.本反演方法克服了传统已有方法计算时间特别长、解稳定性差的缺点,在主频1.99 GHz的微机上,反演128×128×10个密度值的计算时间小于20 s,理论模型和实际资料的应用表明反演具有较好的效果.Due to the restriction of memory and computing speed of computer, most existing techniques for 3D density inversion of the large-area gravity data are ineffective. This paper presents a rapid inversion method for 8D apparent density based on separation and continuation of potential field. The new method is carried out in the following three steps. Firstly, the gravity field on the plane is separated by a cutting method into several parts corresponding to strata of different depth. Secondly, by the way of downward continuation, the field resulted from different strata is respectively reduced to a plane corresponding to its depth. Finally, inversion is conducted to get the structure of apparent density of each stratum, namely, the approximate distribution of density. The method is called apparent density inversion. The inversion technique overcomes drawbacks of long computation and unstable solution, it takes less than 20 seconds to compute a density data set of 128 × 128 × 10 points on a PC of 1. 99 GHz. The method is demonstrated on synthetic models and on real gravity data.

关 键 词：重力异常 三维反演 视密度反演 位场分离 位场延拓 

分 类 号：P631[天文地球—地质矿产勘探]