Method and apparatus for detecting and discriminating objects under the ground

A method of detecting and discriminating objects under the ground, comprising the steps of:

• putting a vibration generating and receiving probe into the ground to bring said probe into contact with an object under the ground;
• hammering said probe to generate an elastic wave;
• receiving, by said vibration generating and receiving probe, the elastic wave which has propagated to the object under the ground;
• converting, by a vibration sensor, vibrations of the elastic wave into an electrical signal and transmitting the electrical signal to a signal processor;
• detecting, by a data processor, frequency response characteristic;
• and
• executing either one of an operation of displaying results of comparison/collation of the frequency response characteristic with data of elastic waves of various objects under the ground collected in advance and another operation of generating an audible sound for discriminating the object under the ground.

An apparatus for detecting and discriminating objects under the ground, comprising:

• a vibration generating and receiving probe which is put into the ground so as to come into contact with an object under the ground;
• a hammer provided in a body of said vibration generating and receiving probe for generating an elastic wave in said vibration generating and receiving probe;
• a vibration sensor attached to said vibration generating and receiving probe for picking up vibrations of the elastic wave which has propagated from said vibration generating and receiving probe to the object under the ground and for converting the vibrations into an electrical signal;
• and
• a signal processor for detecting time response of at least one of one longitudinal wave and two transverse waves of the elastic wave on the basis of the time-series electrical signal from said vibration sensor and for comparing/collating the time response with data of elastic waves of various objects collected in advance.