Development and Laboratory Trials of the Light-Based High-Resolution Target Movement Monitor for Monitoring Convergence at Underground Mines

This paper describes a development and laboratory evaluation of the light-based high-resolution target movement monitor which can be used to measure convergence at underground excavations with submillimeter accuracy. The monitor is based on unique measurement technology which was developed at the University of Missouri-Rolla. This system has the potential for high accuracy detection and monitoring of positional changes (as small as 0.1 mm with the current laboratory implementation) presented by many types of targets located in close proximity to or at far distances from the monitor. The sensitivity of the system to camera resolution and the error analysis as a function of the laser incident angle are described. The system utilizes custom computer processing, a high-resolution camera, and laser light to measure the distance to a target accurately in one dimension, but it can also be used for performing twodimensional surface profiling or analyzing three-dimensional movement of the target. The ability of this optical system to measure ground movement with submillimeter accuracy will allow for monitoring ground convergence in areas of high traffic or which are inaccessible for the installation of traditional ground movement sensing devices.