对缺失频段的瑞雷波频散曲线反演的误差分析

THE INVERSION OF RAYLEIGH WAVE DISPERSION CURVE WHICH LOST FREQUENCY RANGE

在实地勘测调查中获得的瑞雷波频散曲线具有先天的不完整性，存在部分频段受干扰或缺失等情况。通过分析频散曲线的敏感度，来说明地下不同深度地层的横波速度对不同频段数据的敏感程度。本文对一个层状介质模型的频散曲线分别截取1-30Hz，11～100Hz，1～10Hz及41～100Hz的正演数据用于反演．误差分析表明：当丢失敏感区域数据时．反演得到的对应层的速度误差较大;若获得完整的敏感区域数据，可以提高反演精度。这个结果在实地勘测调查中，有利于对数据采集的侧重点。

Rayleigh wave dispersion curves obtained from real world are incomplete, for example, distortions or absence of frequency range. A sensitivity analysis of dispersion curve demonstrates that the sensitivity to S-wave velocity of a layer changes with frequency. An inversion of modeling dispersion curve uses the frequency ranges of 1-30Hz, 11-100Hz and 1-10Hz adding 41-100Hz, respectively. Error analysis shows that the error of the layer＇s velocity is high because of the absence of dispersion data in sensitive frequency range; the resolution of inversion will be improved if we obtain the data of sensitive range. The result is very good for the exploration.