| 摘要 |
<p>PURPOSE:To clear a radio wave method even when the electric power of a sent wave is increased by sending a pulse wave into the ground at different periods and sampling a reflected wave from a buried body in synchronism with the corresponding periods of the sent pulse wave. CONSTITUTION:A pulse generator 4 sends out pulses having N periods T1, T2...TN with trigger pulses from a random signal generator 6. The reflected wave from the object 5 is inputted to a sampling circuit 7 through an amplifier 5' to sample the received wave at timing deviating from each input point of time of the trigger pulses by DELTAt at each other, thereby performing conversion into a low frequency signal whose reception waveform is extended on the time base. This signal is displayed 8 to check whether or not there is a peak by the reflection from the object 5 and the time from the rising of the received signal to the peak position, thereby measuring whether or not there is the object 5 and its position. Thus, the frequency spectrum of the sent pulses decreases uniformly as compared with the constant-period pulse wave, so the limitations of the radio wave method can be cleared even if the electric power of the sent wave is increased.</p> |
