In field practice, a subsurface is mapped by arranging a series of wave-train sources, such as small dynamite explosions, in a grid pattern…

第二句话对解释进行总的说明：“在实地作业中，通过将一系列波列源，诸如小规模炸药爆炸，排列成一个网格模式，从而将地下层面标绘出来。” 接下来是“地震反射法”的详细过程。

youdao

The two cross correlations sum up to realize plane wave imaging at subsurface.

二者互相关求和，实现平面波地下波场成像。

youdao

Wave equation time migration fails to image subsurface geological structure correctly in the case of obvious lateral seismic velocity variation.

当介质的速度在横向上存在较大的变化时，波动方程时间偏移不能使地下的构造正确成像。

youdao

Based on the Phoenix lander, the craft is tasked with giving us a peek beneath the planet's surface, armed with tools that include a geodetic instrument from the Jet Propulsion Laboratory, which will be used to calculate Mars' rotation axis, a seismic wave sensor and a subsurface heat probe, to measure the planet's internal temperature.

ENGADGET: NASA InSight tapped for Mars drilling mission in 2016