Archaeological survey using pulse compression subsurface radar

Abstract

A pulse compression subsurface radar using a chirp signal has been developed and evaluated by experimental survey at an archaeological site. This subsurface radar shows the superior ability to detect buried objects by weaker transmitting power than that of a conventional subsurface radar. Although several types of subsurface radars are now used to probe buried objects, it is sometimes difficult to use them for archaeological surveys. This is because echoes from targets such as tombs, ruins, and old mounds are sometimes very weak owing to their smallness and electromagnetic properties, which are very similar to the surrounding soils. In contrast, a pulse compression radar using a chirp signal has the ability to detect a very weak signal masked by noise, with very high resolution. We have applied this technique to a subsurface radar for archaeological survey and assembled an experimental system of a chirp subsurface radar using a delay correlator for pulse compression. This system has been successfully tested at an archaeological site called ‘The remains of Tajiri’ (Komochi, Gunma prefecture, Japan): a mounded tomb buried in the pumice layer has been clearly detected by this system. Copyright © 2000 John Wiley & Sons, Ltd.