TUNNEL WALL MONITORING DEVICE

摘要

PURPOSE:To obtain high resolution by using fewer wave receivers and without performing position control in a strict up and down direction. CONSTITUTION:A wave transmitter-wave receiver array consisting of a wave transmitter 16 for performing ultrasonic omnidirectional emission and a wave receiver array 18 composed of plural ultrasonic nondirectional wave receivers 24, is provided. The area of a triangle having three adjacent wave-receivers 24 as vertexes along a curved surface is made smaller when the density of information on reflected waves reaching within the triangle is high, and the area is made larger when the density is low.