High-speed computation of gravity and magnetic anomalies in 3-D inversion for physical properties

摘要

A currently prevailing approach in gravity and magnetic inversion, especially in 3-D case is regularly subdividing the source region into a set of juxtaposed cuboids, and estimating the physical properties of the cuboids by using an inversion of potential field, and deducing the image of the geological sources. If nonlinear global methods used in the inversion, the paper shows that there exists an excessive computation that has bottlenecked the effectiveness of the methods. Several special tricks have been taken to break the choke point of overwhelming computation, one of which is to separate the geometric trellis from formulas. The trellis is invariable during the whole process of inversion, and can be stored as a table, which would make the following reiterative forwardcompu-tation as just a simple reading of the table and multiplying it with corresponding properties of the geometric cells. The caused huge storage of geometric trellis has been tremendously reduced by a very skill of e-quivalent storing. The approaches revive the nonlinear methods in their applications to the inversion of gravity and magnetic anomalies for 3-D physical properties.