Comparison of Precision in Pointing to Various Targets at Different Distances

The purpose of this research is to compare the horizontal angular precision in pointing to commonly used surveying targets using an optical theodolite. The results of the research are intended to give surveyors and their field crews guidelines for choosing the best targets for different sight distances. Several targets located at various distances were observed by three instrument operators. Differences in the precision of pointings were observed with different targets and sight distances. Differences in pointing precision between observers appear to be statistically insignificant. Some combinations of target and target distance produced smaller standard deviations and were considered \u27better\u27 targets. Physical stability of a target was of primary significance with a tripod-mounted target being superior to a hand-held plumb bob, range pole, or prism pole