UNDERGROUND RADAR APPARATUS FOR GUIDED DRILLING METHOD

摘要

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.