Relatively familiar with the time domain, frequency domain is very helpful to understand and master the many effects of signal integrity between the two can be FFT conversion.

The Du-conversion is one that converse the signal from time domain to gate-width domain and uses the wide spectrum density of the signal to show its characteristics.

A method for deriving the smoothed ground surface from CMP datum of static correction is given to form a common datum for velocity spectrum, time-depth conversion and depth migration in depth domain.