层速度谱

Interval velocity spectrum.

层速度是地震勘探中需要求取的一个重要参数。目前普遍采用的方生是由速度谱先求取叠加速度,然后再用Dix公式求取层速度;另外,还有新发展起来的计算层速度的层析技术。这两种方法都存在缺陷,不能满足实际工作的需要。为此,本文提出了层速度谱方法,它是将层析技术与速度谱思想有机地结合起来,形成了一个求取层速度的崭新方法。它吸取了两法的优点,克暇了它们自的缺点;充分利用了观测波场的旅行时信息和振幅信息,但不需要拾取旅行时,全部计算工作自动完成。同时利用特征分析方法,提高了层速度计算的抗干扰能力和分辨力。

Interval velocity is an important parameter that must be solved in seismic exploration. The usual method for obtaining interval velocity is to derive stacking velocity from velocity spectrum, then to calculate interval velocity by Dix formula. In addition,seismic tomography is also used to obtain interval velocity. Unfortunately, both of them are imperfect and fail to offer satisfactory results in computing interval velocity. Hence, interval velocity spectrum method was newly proposed, which combines seismic tomography and velocity spectrum ingeniously. The new method inherits their advantages but removes their imperfections. It makes full use of travel time and amplitude informations of the observed wave field, without the travel time picked. Computation is done automatically, and this new method offers good both noise resistance and high resolution because the characteristic analysis means is performed here.