Reflector-less total station measurements and their accuracy, precision and reliability

Abstract

Despite the vast technological advancements in equipment, the survey industry continues to struggle with the collection of data relating to inaccessible points. While the introduction of reflector‐less total stations has meant that inaccessible points can now be measured with relative ease, there are some questions as to the accuracy and reliability that can be achieved with such equipment. The object of this study is to determine likely limits for reliability of reflector‐less instruments especially in relation to measurements with large angles of incidence, but also looking at the vagaries caused by differing materials and beam divergence. The study has been carried out in various locations using Trimble S6 and S8 reflector‐less total station equipment to a variety of surfaces materials and shapes. This study suggests that angle of incidence of the measurement signal to the surface of the measured material has a large influence on the accuracy of that measurement. In the search for accurate survey results from inaccessible points, it becomes necessary to ensure that crucial measurements are checked as well as having a good understanding of reflector‐less instruments capabilities