Coded pulse signal subsurface radar

Subsurface radar to detect buried objects from the ground surface by using electromagnetic waves has been used widely for detection of buried pipes since a shallow subsurface zone of up to 2 to 3 m can be visualized with high resolution at high speed. On the other hand, deeper subsurface detection is required in searching for archaeological ruins. In this paper, a delay correlation-type subsurface radar using monocycle pulse signals modulated by M-sequence codes is proposed with a view to expanding the search range by increasing the average energy of the transmitted signals. With a test setup, a steel pipe buried 2.5 m below the ground surface was detected with a transmitting power of 1 mW. In regard to the maximum detectable range of the subsurface radar using this type of coded signals, this paper carries out a study from the point of view of both the time side-lobe and S/N. © 2001 Scripta Technica, Electron Comm Jpn Pt 1, 85(2): 8–16, 2002