Deformation monitoring of a slope by vision metrology

This paper discusses monitoring of slope deformations by vision metrology with a CCD camera. Reflective targets are placed over a slope, and their object coordinates is measured by a photogrammetric technique. Precision and sensitivity of slope deformation measurement using vision metrology are investigated. Deformation of targets placed on a slope was detected by measurement at two time epochs using hypothesis testing, and a series of equations is derived for the detection. The strengths of the observation networks were evaluated from three view points, i.e. precision of target object coordinates, sensitivity of observations and reliability of observation. Model experiments were carried out to verify the method’s validity. A slope model of 1.1 m × 0.5 m in size was constructed. An reasonable exposure configuration is looked for, which is capable of detecting displacement of about 2 mm pro 30 m. It is thus clarified that sufficient precision, sensitivity and reliability are achievable for practical use by a total of 12 exposures: four for each of three locations.