Underground pipe detector

Claim 1

In a system for detecting and identifying targets situate beneath the surface of the ground where generating means serves to generate discrete pulses of short duration for effecting broad spectrum electromagnetic radiation and apply said pulses through input terminals to antenna means, said system further including means including output terminals for receiving and operating, in time domain fashion, upon pulse reflection detected by said antenna means, the improvement comprising: a composite antenna including: a pair of axially aligned oppositely extending nonresonant transmitting arms, each said arm being electrically coupled with the feed component of a said input terminal; a second pair of axially aligned oppositely extending nonresonant receiving arms, each said arm being electrically coupled with the feed component of a said output terminal, said second pair of arms being arranged in orthogonal axial relationship with the axis of said transmitting arms; each said pair of transmitting and receiving arms being configured having wave energy absorbing characteristics minimizing pulse reflection developed within said antenna, and each said arm thereof extending from a respective said feed component coupling to terminate in symmetry at a common mutual connection; and said composite antenna being configured to operate at locations closely proximate the said ground surface to enhance the coupling of electromagnetic energy between said antenna and the ground.