Relevelling is required after cultural editing. Each of the cultural editing procedures described in this paper has advantages and disadvantages. Table 1 lists the major advantages and disadvantages of the manual and automatic methods, with semi-automatic methods falling somewhere in the middle. Automatic techniques that remove the high frequency response from HRAM data without detailed checking against known and suspected culture are more likely to remove a portion of high frequency geological signal along with the cultural noise. This may or may not be acceptable, depending on the objective of the survey.
Automatic methods are fast and hence less costly than manual methods.
In some cases time and cost are of the utmost importance. They are, of course, somewhat slower and more expensive. Manual techniques are slower and more expensive because they require considerable hands-on interaction. These methods are more selective of the noise and generally remove less high frequency geological signal than automatic methods. The ability to remove all noise and to leave all the geological signal is directly dependent on the skill of the geophysicist doing the interactive editing and the quality of the databases used to create known man-made features.