摘要
将神经网络反推算法（ＢＰ算法）引入重、磁场反演，建立了基于神经网络原理描述反演过程的模型，并在通用数字计算机上实现了一种拟ＢＰ算法，实践表明，拟ＢＰ算法作重磁资料反演，具有快速，大维数，容错能力强和便于充分利用已知信息等特点，用ＢＰ算法对湘南地区作重磁参数反演，给出了本区的磁性，密度三维分布特征，进而对本区地壳结构和地质构造得出了新的认识，取得较好效果，神经网络算法的引入，可能带来地球物理场反演方法的革新。
The Back Propagation algorithm（BP algorithm）of artificial neural networks was intro-duced in the inversion of gravity and magnetic data，and at the same time the models of inver-sion process based on the principle of BP algorithm was established．We design an inversionprogram which can be executed on the Neumann computer，and by using a fast forward calcu-lating method in this program，the inversion speed is much quicker than traditional method.As a result，using this inversion algorithm the interpretation of gravity and magnetic data canbe done more precisely，more quickly and more flexibly．We used the proposed method insouthern Hunan area，and the 3-D physical properties （densities and magnetizabilities）distri-butions in this area were calculated from the 1 ：200000 gravity and magnetic data，The map-ping depth is 10 km，3-Dunits size is 4 km×2 km×0．1 km。1200 observation station datawere fitted，whose fitting accuracy is 8．0× 10^(-6)m/s^2 for gravity and 3．5nT for magnetic.With the geology interpretation of the 3-D gravity and magnetic inversion，the Predevonian u-plifts and concealed rock bodies were successfully delineated，different types granites were i-dentified，and a new rock zone with west-east trend was confirmed in 1992.
基金
中国有色金属工业总公司重点科研基金
关键词
神经网络
BP算法
地磁学
artificial neural networks；BP algorithm；inversion；gravity and magnetic field
