The Study On Real-time Visual Inversion Of Gravity And Magnetic Anomalies For 3D Physical Properties

Traditionally,3D gravity and magnetic inversion and evaluation on the inversion result are two independent work procedures. The inversion calculation normally is time-consuming and the result has a limitation of immediate evaluation. Besides, based on the current result evaluation, inversion algorithm parameters commonly have to be adjusted for the next calculation. Repeat this procedure for chasing the ideal result. This inversion working mode can be viewed as a very inefficient one. Due to these drawbacks, this paper proposes a new research topic on process of gravity and magnetic data by combining inversion calculation with data 3D visualization and by enabling interactive operation on inversion process to promote the reasonability of inversion result and the efficiency of calculation process.To achieve the object, the following aspects have been researched and fulfilled.Firstly, the research works on automatic inversion technology for 3D gravity and magnetic physical properties inversion for observed data measured on terrain. A new forward calculation method is proposed for terrain observed point. The purpose of this method is to realize direct forward calculation, which using geo-frame equivalence between layers. Combined with "random sub-region" inversion method, rapid and automatic 3D inversion for gravity and magnetic physical properties based on terrain observed data is implemented.Secondly, in the process of interactive visual inversion, intermediate inversion result has to be smoothed by filtering in order to guide the ensuing inversion calculation. Therefore, we researched and then realized two kinds of smooth filtering algorithm for 3D volume physical properties data:average smoothing method by using 3D matrix operator and nonlinear smoothing method by using 3D sub-domain operators. These algorithms have been fulfilled by parallel programming. Thirdly, based on analysis and summarization on the characters and demands of visual inversion,3D visualization displayed in an integrated environment has been implemented. The research dissects the inner mechanism of VTK (visualization toolkit) and the core of VTK data structure and then the elaborate implementation of 3D visualization graphic elements is provided.Finally, the application software with integrated environment has been designed for real-time visual inversion. In this software project, there are two difficult issues:how to achieve real-time visualization while inversion calculation is heavily running? How to edit inversion parameters and ask inversion calculation thread to use the changed parameters in real-time way? By multi-threaded programming and data synchronization mechanism, the solutions of these two issues are provided.The research in this dissertation has an exploratory significance for study and development on the technology of real-time visual inversion in geophysics field.