| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method and an apparatus for the measurement of the probing distance of an underground probing radar for a tunnel excavator, where the measurement is not complicated, the measurement can be performed at low costs, it is possible to immediately deal with a change in a medium at a measuring site, and high measurement accuracy can be obtained. SOLUTION: When a prescribed signal is transmitted, in advance from a transmitting antenna (12) in an integrated transmission-receiving antenna toward a reference medium having a known relative permittivity (εr0 ), the signal is received by a receiving antenna (13), and a first reception waveform (B0 ) is obtained. On the basis of a waveform (B0 ), an arrival time (t0 ) of direct waves (16) in the reference medium is found to be stored. After that, in the actual underground probing operation, the second reception waveform (B1 ) of the prescribed signal transmitted toward natural ground is obtained; on the basis of the waveform (B1 ), an arrival time (t1 ) in the natural ground is found; the relative permittivity of the natural ground is found, on the basis of the arrival time (t1 ), the arrival time (t0 ) in the reference medium and the relative permittivity (εr0 ) of the reference medium; and a distance (L) up to a reflecting object is found, on the basis of the found relative permittivity of the natural ground and an arrival time (t), up to the reflecting object in the natural ground.</p> |
