The precondition of RG line being as datumof time-depth conversion is that the RG line is equivalent to the smooth line of surface elevation.
RG线作为时深转换基准面的前提是RG线等效于地表高程的平滑线。
2
Actually, floating datum is still horizontal datum, but the datumelevationof different CMP is variable.
实际上浮动基准面还是水平基准面,只是不同CMP的水平基准面高程可以变化。
3
The transforming of survey datum and the control of axis, vertical level, elevation are of great importance on controlling quality of high-rise building construction.