Development of a method to estimate velocity structure using drill bits as a seismic source

1.信号处理研究：研究了一种从连续钻进信号中提取速度结构信息的方法。研究表明，通过分析三维流图，可以在时间域和频率域中提取速度信息。反演研究：我们研究了一种利用1中的技术获得的信息来模拟速度结构的方法。我们发现，使用分层模型可以模拟出与实际结构一致的速度结构。方法的评估：通过使用在索尔茨收集的真实数据集来评估1和2中研究的方法的性能。研究了该方法在处理过程中存在的问题和局限性，并反馈到开发阶段1和2。

1. Investigation on signal processing : We investigated a method to extract information on velocity structure from continuous drill signals. It has been revealed that velocity information can be extracted by analysis three dimensional hodograms in both time and frequency domains.2. Investigation on inversion : We investigated a method to model velocity structure using information obtained by the techniques in 1. We have found that velocity structure consistent with real structure can be modeled by using a layerd model.3. Evaluation of the method : Performance of the methods studied in 1 and 2 are eveluated by using real data sets collected at Soultz. Problem in processing and limitation of this method are examined and fed back to the developing phase 1 and 2.