PURPOSE: To detect exactly the position of a target under the ground by moving a transmitting and a receiving antennas in one direction along the surface of the earth, deriving a mutual correlative signal in many positions on the surface of the earth, and adding these signals.
CONSTITUTION: A reference waveform is generated by considering the ripple of a waveform by a characteristic of an antenna 2 itself, and the mutual correlation of this reference waveform and a measured waveform is derived, to obtain a mutual correlative signal which has a peak of one level at the time corresponding to the transmitting and receiving position and the range of a target 4 by regarding the transmission time as the reference time, and the preceding and succeeding parts at the other level. The converted value of this correlative signal is distributed equally onto the circumference around a position corresponding to the surface of the earth of its signal having a radius of a range extending from said position to a place where its converted value exists, and it is added as to each mutual correlative signal. In this way, the sectional image of a distinct target 4 is obtained, and the position of the target under the ground can be detected exactly.
HIRAOKA TSUTOMU
TSUNASAKI MASARU
