METHOD AND APPARATUS FOR DERIVATION OF PROBING CAPABILITY AS WELL AS PROBING APPARATUS

PROBLEM TO BE SOLVED: To automatically derive an effective reflection depth which indicates how deep a probing signal can be reached effectively and from which object the probing signal is reflected so as to be returned without knowing a medium constant regarding a wave signal which is propagated in a medium to be probed. SOLUTION: While a probing apparatus is being moved on the surface of a medium 1, a wave signal 4 by electromagnetic waves or sound waves is radiated into the medium 1, a reflected signal from an object 2 existing in the medium 1 is received, and the two-dimensional image data is generated on the basis of a received signal while a movement distance (x) on the surface of the medium and the reflection time (t) from the object of the wave signal are set as cooordinates (x, t). On the basis of the two-dimensional image data, one- dimensional reflection time intensity distributions at the input end and the output end of a receiving circuit are found, and effective reflection times which are used to judge the effectiveness of the received signal are found on the basis of the two reflection time intensity distributions, and the effective range of the reflection time (t) is found on the basis of the smaller effective reflection time.