多震相走时联合三参数同时反演成像

Simultaneous inversion of three model parameters with multiple classes of arrival times

采用新近研制的分区多步不规则最短路径多震相地震射线追踪正演技术,结合流行的子空间反演算法,提出了一种联合多震相走时资料进行地震三参数(速度、反射界面和震源位置)同时反演的方法技术.数值模拟反演实例、以及与双参数(速度和反射界面或速度和震源位置)同时反演的对比分析表明:三参数同时反演成像结果大体接近双参数同时反演成像的结果.另外,噪声敏感性试验表明:所提算法对到时数据中可容许的随机误差并不敏感,结果说明多震相走时的联合三参数同时反演成像方法技术不失为一种提高走时成像空间分辨率、进而降低重建模型参数失真度、行之有效的方法技术.

By exploring a newly developed multistage irregular shortest-path ray tracing algorithm and combining with the subspace inversion solver, we in this paper develop a simultaneous traveltime inversion method for updating both the velocity fields, reflector geometries and source hypocenter locations by using multiple classes of arrival times. The numerical simulation inversions and comparison with the two parameter （velocity and reflector geometry or velocity and hypocenter location） inversions indicate that the results of three model parameter inversion are approximate to the two model parameter inversion. In addition, the new developing simultaneous inversion algorithm is not sensitive to a tolerable noise in the traveltime data, which verifies that the inversion methodology is a practical and efficient way to improve the spatial resolution and reduce the artifacts in reconstructing the three model parameters.