| 摘要 |
<p>PURPOSE:To reduce an area where surveying is impossible nearby the ground surface and to increase survey depth by varying the pulse width, i.e. frequency and pulse amplitude of a radio wave oscillated by an oscillator according to observation depth. CONSTITUTION:A transmitting antenna 1 is applied with a pulse signal from the oscillator 5, which is controlled by a control signal generator 6 to vary the amplitude and pulse width of the oscillated pulse signal. A signal received by a receiving antenna 2 is amplified 7 and further sampled by a sampler 8. This sampled signal is led to a video processor 9, where the signal is made into video and displayed 10. Further, the video processor 9 inputs the position of a carriage 3 where the antennas 1 and 2 are mounted from a position detector 11. Then, the amplitude and frequency of the oscillated pulse signal are varied according to the observation depth and the pulse width is made short as the time of an observation nearby the ground surface, so the area where detection is impossible owing to ground surface reflection is reducible. Further, the attenuation of a reflected wave from a deep surveyed target can be decreased, so the survey depth can be increased.</p> |
