初至

基于惠更斯原理，给出了一个简练的初至到时算法，并应用于地震走时层析成像。

A simple and efficient method is proposed for calculating first arrival traveltime based on Huygens ′ principle , and applied to seismic traveltime tomography .

根据云南和四川地震台网174个台站记录的4625个区域地震初至P波和S波走时资料，并结合其它深部地球物理资料，确定了川滇地区地壳上地幔三维速度结构。

Based on the first arrival P and S data of 4 625 regional earthquakes recorded at 174 stations dispersed in the Yunnan and Sichuan Provinces , the 3-D velocity structure of crust and upper mantle in the region is determined , incorporating with previous deep geophysical data .

利用三分向地震数据，提出了一种自动检测P波和S波初至的算法。

An algorithm has been developed for automatic picking P-and S-phase of three-component seismic data .

地震波记录曲线的分析表明，初至波是P波，随后是S波。

The analysis of seismograms indicates that the first arrival is a P-wave , followed by a S-wave .

BP神经网络的改进及其在初至波拾取中的应用

The improved BP neural network and its application in seismic first breaks picking

对MR曲线的截距变化曲线进行类似于坐标旋转的校正，使对应信号初至的拐点成为曲线的极小值，有助于信号初至的自动检测。

In order to detect arrival time of signals automatically , the intercept curve was corrected using a method that similarly to coordinate rotation .

结果表明：πg波的初至波速为6.00km/s，与Press的结果相近；

The results show that , The first velocity is 6.0km / s , it is close to Press 's results ;

P波时差法对于信号信噪比要求高，信号的初至时间很难精确提取，人为因素过大。

The results showed that P-wave method requires high signal-to-noise ratio , difficultly observes the beginning time of seismic wave , and is highly affected by human factors .

在场地波速测量中，由于噪声等因素的影响，很难准确识别P波、S波的初至时刻，致使波速结果存在很大的误差。

It is difficult to identify the arrival time of P and S waves in wave velocity logging , which yields great error for P and S wave velocities .

Kriging方法在初至层析静校正中的应用

Application of Kriging Method in the First Arrival Tomographic Statics Correction

Hausdorff分数维识别地震道初至走时

Distinguishing seismic first break by means of Hausdorff fractal dimension

这类PS转换波与初至P波之间的到时差，可用来测定地壳和上地幔构造。

The difference of arrival times between such PS and PP waves can be used to determine the structures in the earth 's crust and upper mantle .

本文利用PS转换波与初至P波的到时差，提出一种不需要拾取P波和转换波震相的转换界面偏移成像方法。

To avoid the difficulty of picking up transmitted P-wave and converted wave phases , this paper proposed a converted wave migration method by estimating the travel time difference between PS converted wave and PP transmitted wave .

为了进一步提高BP网络拾取地震波初至的抗干扰能力，该文提出了应用小波变换对地震波信号进行预处理来消除噪声影响。

To enhance the antinoise ability of this algorithm for detecting the first arrivals on seismic waves , the paper applies the wavelet transform to conduct seismic wave data preprocessing for eliminating the influence of noise .

试验结果证实，将随机噪声衰减技术用于VSP资料处理，可以有效地提高信噪比，改善初至拾取的精度。

The experimental result proves that the application of the random noise attenuation technique to VSP data processing obviously improves signal-noise ratio and first break pickup .

本文在分析和研究BP神经网络内在并行性的基础上，基于MPI设计与实现了改进型BP神经网络的并行化算法，并实现了地震初至拾取的并行处理。

We have designed the modified BP NN parallel arithmetic based on the research of instinctive parallelity in BP NN and the MPI ( Message Passing Interface ), and realized the parallel processing for the seismic first picking .

对于这样的初至波，进行广义线性反演（GLI）有可能给出一个合理的近地表结构。

The generalized linear inversion ( GLI ) of such first breaks can bring a reasonable near-surface structure .

利用Radon变换分离出射孔资料的直达波，拾取初至并进行反演，反演结果与射孔位置的误差满足微地震反演精度要求。

Using Radon transform to separate direct waves from whole wave field of perforation , picking up first arrival and inversing , the residual of inversion result and perforation location meets the precision requirement of micro-seismic inversion application .

通过利用井间地震初至波的旅行时及其频率特性进行地层地震速度和岩石Q值的联合层析成像，就可以综合利用地震波的运动学和动力学特征对井间储层进行更精确的描述。

It can describe precisely the cross hole reservoir by using synthetically the kinematic and dynamic features through using travel time and frequency feature of cross hole seismic first break for joint tomographic imaging for seismic velocity of stratum and for Q value .

为了从零偏VSP初至波变化中，提取更多的有用地球物理信息，首先应该消除因震源子波不同而造成的影响。

In order to derive more useful geophysical informations from the variation of the first break of zero-offset VSP data , the impact caused by the difference of source wavelet should be eliminated at first .

第二阶段是对随钻地震信号处理过的资料做逆VSP处理，包括初至拾取、速度分析、波场分离、反褶积、走廊叠加和CDP转换迭加成像等。

The second is RVSP processing on the data after signal processing . including the first break picking , velocity analysis , wave field separation , deconvolution , transform the corridor stack , and CDP-tansform .

经测试表明：在一条二维地震测线上，对每一道检波器分别采用声学定位及初至波二次定位，两者间误差均在5m以内。

It is shown by the practice that , using sonic positioning and first breaks secondary positioning respectively for each geophone in a 2D seismic line , the positioning errors for two methods were all within 5m .

地面重锤横向敲击枕木激发的水平分量的SH型横波数据信噪比较高，其垂直分量纵波初至的信噪比不高；

The S / N ratio in SH-wave data of horizontal components shooting by hammer on the surface hammering at sleeper laterally is higher , but S / N ratio of the first breaks of P-wave in vertical components is not high ;

地震记录初至拾取在层析成像勘探、折射波静校正、VSP解释和浅层折射波勘探中起重要作用，它的准确程序直接影响着处理结果。

The automatic pick of seismic first arrivals plays a key role in seismic data processing such as refraction static correction , VSP data interpretation , shallow refraction exploration and seismic tomography , as the accuracy directly influences the processing result .

根据Mandelbrot-Richardson曲线截距的变化，可以准确检测到地震信号的初至。

The change of intercept of Mandelbrot-Richardson curve can be used to estimate arrival time of seismic signal accurately .

通过对实际资料的系统分析，我们不能利用DMO反演法，移动震源VSP反演法和多偏移距VSP初至旅行时反演法提取Thomsen参数用于各向异性地震资料的处理。

By conducting a systematic analysis , we have found that the DMO inversion , the walkway VSP inversion and the multi-offset VSP travel time inversion could not estimate the Thomsen anisotropic parameters used in anisotropic seismic data processing .

根据天水地震台SK地震仪近年来记录的338个震例的资料，用最小二乘法求出最大振幅面波与初至波到时差同震中距的关系式，并与JB表进行了对比。

According to records of 338 earthquakes in recent years by SK seismograph of Tianshui seismic station , a formula of relationship between travel time difference of maximum surface wave from primary wave and epicentral distance is given by least squares method .

初至的拾取在地震资料处理中有着非常重要的作用，它是折射波资料分析、VSP处理和井间地震资料处理的基础工作，并为其他处理工作提供可靠参数。

First break picking plays an important role in seismic data processing , which is an essential work for refraction data analysis , VSP processing and cross-well seismic data processing , and provides reliable parameters for other processing . First break picking technology is put forward based on S-transform .

除此以外，进一步实现了基于pi-sigma模型的模糊神经网络方法，并应用计算机模拟的理论数据验证了神经网络方法初至拾取的可用性。

Farther , the FNN ( Fuzzy Neural Net - work ) based on the pi-sigma module was achieved . The ANN methods have been approved available in seismic first break picking by applications in theory data .

声波测井资料弱初至波检测新方法

New Method for Weak First Arrival Picking from Full Sonic Waveform