最大熵走时波形层析成像

Maximun entropy traveltime-waveform tomography

1. 国家地震局物探大队, 郑州450003;2. 中国地质大学(北京), 北京100083

Geophysical Prospecting Party,S. S. B.,ZHcnzou City,Intercode: 450003

本文以LuoYi(1991)提出的波动方程走时反演(简称WT反演)方法为基础, 将最大熵原理引入到WT反演方法中, 形成了最大烟走时波形层析成像方法。在该方法中, 利用n步重新开始的PRP共轭梯度法对理论走时与观测走时进行最小二乘意义下的最佳拟会。数值试验表明, 这种方法抗噪声能力强, 分辨率高, 很适合于有限观测数据并且含有噪声的数据成像。对深地震测深观测资料进行了成像试验, 并与射线CT的结果作比较, 结果表明, 该方法是行之有效的。

Based on wave-equation traveltime inversion (WT) advocated by Luo Yi et ai (1991),this paper proposes a method Called maximun entropy traveltime-waveform tomography which is derived by inttoducing the concept of maximun entropy into WT inversion. The best fitting between theorethal and observed traveltimes is odculated via the PRP conjuate gradient method which can be re-interated at nth step. Numerical tests show this method is powerful in resistance to noise and is of high resolution,therefor suits to image finite and noisy data. The imaging test on deep sounding seismic data and its comparison with the result of ray tomography show the method is feasible.