Monitoring displacements at large dams by means of precision traverses

Abstract

The paper presents the results of a test on the angular accuracy of a motorized tachymeter recently used for precision traversing during the first fill of a portuguese large dam. Angular measurements were carried out at two precision traverses, one at the crest of the dam and the other at an inspection gallery. Horizontal angles were measured with the automatic target recognition procedure of the motorized tachymeter and with a conventional electronic theodolite, with prior equivalent accuracy. Statistical inference methods were used to test the accuracy of automatic angular measurement against conventional measurement.