Accuracy Evaluation of Long-Range Reflectorless Distance Measurement

Abstract

Reflectorless total station (RLTS) has made it possible for only one person to carry out field measurements and inaccessible points can be measured with relative ease. There is no sufficient information about the accuracy of these instruments for the long range measurements. This paper attempts to evaluate the accuracy of reflectorless distance measurements ranging up to 1000 m and to determine the surface area needed for such measurements at different incidence angles. An experiment was carried out to examine what effect surface material, target size and incidence angle had on distance measurement. In this experiment 10 different distances were measured using targets of 6 different materials and 4 different sizes at 5 different incidence angles. To properly evaluate the results, a special supporting base was designed and manufactured for holding the reflecting targets to ensure accuracy in the evaluation. Based on the accuracy analysis of a lot of testing results, the conclusions that were drawn indicated that the target size had a great effect on the accuracy if the incidence angle was between 15 &#176 and 30 &#176 .