| 摘要 |
PURPOSE:To eliminate an error in position detection due to an error in estimation and to perform high-accuracy position detection by providing a display means which displays an echo image of an underground buried body by using the depth direction of the underwater buried body and the moving direction of a moving carriage as parameters. CONSTITUTION:A pseudo echo image 5 of the underwater buried body is displayed on a display part 210 at an optional positions and its peak mark Q and expansion coefficient alpha are varied by pressing switch images of display parts 211 and 212 to put the echo image 4 of the buried body 3 within its interline area. In this case, two echo images 4 and 5 are overlapped with each other to find the coordinates of the peak position P of the echo image 4 of the buried body 3 as the coordinates (x0, t0) of the peak mark Q of the artificial echo image 5. Further, the expansion of the opening part of a hyperbola forming the echo image 5. Further, the expansion of the opening part of the hyperbola forming the echo image 4 is also found from the value alpha of the expansion of the pseudo echo image 5. Consequently, a radio wave propagation speed Vg is found from Vg=2alpha and the need for a measuring instrument which measures the specific dielectric constant of soil is eliminated. |
