基于剩余异常相关成像的重磁物性反演方法

3-D gravity and magnetic inversion for physical properties based on residual anomaly correlation

将场源区剖分成长方体单元,通过采集的重磁数据反演出这些单元的密度或者磁化率变化,勾画出场源的分布图像,这种方式是重磁三维反演的重要方向.重磁相关成像通过计算测量的重磁异常与地下各点在测区上的重磁异常的归一化相关,显示出异常地质体的空间赋存状态和等效剩余重磁物性.该方法计算速度快,方法简单、稳定,但是反演的结果只是在-1到+1之间的等效物性,不能够直接反演剩余密度或者磁化率,并且无法引入已知的地质约束.本文通过对物性模型的正演和实测结果的残差进行相关成像,迭代更新物性模型实现对物性参数的反演过程.模型实验证明该方法相对相关成像不仅能提高分辨率,还能够得到真正的物性参数.

It is a main research direction to outline the source distribution from the imaging result of the gravity or magnetic inversion based on rectangular units. Correlation imaging of gravity and magnetic is a method that calculates the normalized correlation of the anomaly of rectangular unit and acquired anomaly. The result can outline the properties distribution and earth structure. The correlation imaging method is characterized by fast computation, stability, and simplicity, but it results in values between --1 and 1 but not the real physical properties, and also can＇t use the prior geology information. In this paper, we proposed a method based on the correlation imaging of the residuals of acquired data and forward data based on a physical model; after some iterations, we get the physical property model. The model test verified the effectiveness of our method.