UNDERGROUND RADAR APPARATUS FOR GUIDED DRILLING METHOD

• Main Authors: HIRAHARA TETSUYA, SUZUKI MORIO, NOZU TOSHIMITSU
• Format: Patent
• Language: English
• Published: 31.07.2002
• Edition: 7
• Subjects: ANALOGOUS ARRANGEMENTS USING OTHER WAVES; BLASTING; DETECTING MASSES OR OBJECTS; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; EARTH DRILLING; ENGINEERING ELEMENTS AND UNITS; FIXED CONSTRUCTIONS; GALLERIES; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; HEATING; JOINTS OR FITTINGS FOR PIPES; LARGE UNDERGROUND CHAMBERS; LIGHTING; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION ORRERADIATION OF RADIO WAVES; MEANS FOR THERMAL INSULATION IN GENERAL; MEASURING; MECHANICAL ENGINEERING; MINING; PHYSICS; PIPES; RADIO DIRECTION-FINDING; RADIO NAVIGATION; SHAFTS; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; TESTING; THERMAL INSULATION IN GENERAL; TUNNELS; WEAPONS

PROBLEM TO BE SOLVED: To provide an underground radar apparatus for a guided drilling method enabling the processing and displaying of signals to follow drilling speed, while being economical. SOLUTION: The underground radar apparatus for the guided drilling method includes a plurality of antenna elements AT1 to AT4 positioned along the outer peripheral surface of the front end of an underground drill moved in the direction of a rotation axis while rotating under the ground; the characteristics of the antenna elements are synthesized to form a nondirectional synthetic antenna around the rotation axis. The radar apparatus includes an estimating and reporting means which estimates that the signal received by the synthetic antenna contains a wave reflected by a reflecting object and then transmits a report signal indicative of it to an above-ground device if the amount of delay at the time of reception of the signal received by the synthetic antenna is generally monotonously increased or decreased over a predetermined length or more in the moving direction and if a change in the amount of delay in the moving direction is equal to or greater than a predetermined value.