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折射波法是一种能把全球规模的深层地壳构造和浅层近地表地下速度进行成像的成熟方法,通常与在地表(或水底)布置检波器排列、记录从地表或近地表激发的震源波至有关。在理想的情况下,当一个界面是速度陡增的分界线时,首波折射波至由射线路径描述,它随弓形射线波入射界面,并沿该界面折射,然后随弓形射线波传回到检波器所在的地表(或水底)。如果这些波至的信噪比(SNR)足够高,那么就可以在炮道集中拾取,并经过转换,在勘探尺度或全球尺度上用层析成像法做旅行时层析成像。不过,在常规折射波层析成像中有两种常见的限制条件:①长偏移距初至折射波的信噪比很差,由于球面扩散、衰减和环境噪声的缘故,在一定的炮检距之外,首波折射波的信噪比
Refractometry is a mature method of imaging deep-sea crustal structures and shallow sub-surface subsurface velocities on a global scale, often associated with arranging geophones at the surface (or bottom), recording source waves excited at or near the surface To the relevant. Ideally, when an interface is a steeply increasing demarcation line, the first wave refracted wave is described by a ray path that enters the interface with the arcuate ray and refracts along the interface and then returns with the arcuate wave The surface (or bottom) where the detector is located. If these wave-to-signal-to-noise ratios (SNRs) are high enough, they can be picked up centrally and converted to travel-time tomography using tomography at exploration or global scales. However, there are two common limitations in conventional refraction tomography: (1) the signal-to-noise ratio of the first-arrival refracted wave at long offsets is very poor due to the spherical spread, attenuation and environmental noise, From outside, the first wave refraction wave signal-to-noise ratio