On the Trilaterlation with Laser Ranger

It is possible to measure a long distance with precision by using an electromagnetic wave. Recently the distance between the triangulation points can be directly measured with Laser Ranger. In triangulation surveying, the advantages claimed for an electromagnetic ranger are as follows : (1) In a large triangulation net, the length of the base line itself can be measured without making the short base line longer by a triangulation net of the base line. (2) It is possible to measure all angles and distances. (3) Distances alone can be measured, by which the co-ordinates of the triangulation points can be determined. The variation of ground strains can be observed by the above (2) method. The main purpose of this study is to make a comparison between the accuracy attained when each of the above three methods is applied.