| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve the reliability of automatic detection by displaying a pseudo echo image determined by the position of maximum point of a received signal and a radio wave propagating speed or dielectric constant when the calculated radio wave propagating speed or dielectric constant is within a fixed range. SOLUTION: A transmitter-receiver device 28 emits an electromagnetic wave into the ground while moving in the ground, and receives the reflected wave from a foreign matter. A signal processing device 38 compares the reflected wave signal received by the device 28 in each of different search distance positions in the same advancing direction, and judged whether the radio wave propagating speed V or dielectric constantεcalculated on the basis of the reflected wave signal is within a prescribed range according to the earth quality in searching or not. A display device 40 displays the image by the reflected wave signal inputted through the device 38. When the speed V or dielectric constantεis within a prescribed range, the device 38 judges the image by the corresponding reflected wave signal to be the image from a true foreign matter, and determines and displays a pseudo echo image by the position of maximum point of the image, the speed V, and the dielectric constantε. Thus, the confirming work after automatic detection is facilitated.</p> |
