Applied Research Of The Total Station Elevation Surveying Using Midway Method In Precise Trigonometric Leveling

It is high accuracy of the distance direct leveling that the ground order by the method of direct leveling, and it most commonly used for the vertical control netword being built.But for the area of more ups and downs ground level, the method's progress slowness, even very difficult or can't carry on. This kind of environment descend, the method that usually uses trigonometric leveling delivers a high distance. The trigonometric leveling is a common method in current engineering control survey. With the popularization of distance measuring instruments with high accuracy, the control netword being built by trigonometric leveling instead of direct leveling can speed up the pace of field survey. An analyzes the principle, error sources and precision of triangulated height surveying, In addition, analyze on error of trigonometric leveling and proper methods given for it can improve the accuracy of observation data. A vertical survey calculation formula using the total station midway method was deduced. The error transmission principle was applied to derive the formula, and the impact of various factors on elevation survey accuracy were analyzed and calculated. This paper uses the total station of the LAICA TCA2003 ,use total station elevation surveying using midway method instead of the fourth direct leveling feasible research in the area of complex and difficult conditions.Verified by experiments, it was confirmed that the total station could replace the water level in elevation surveys with the precision meeting the grade three and grade four specifications for direct leveling within certain ranges. Several proposals were presented to increase elevation surveying precision. In the end, this paper introduced the midway method trigonometric leveling in the Gutan Tianbao actual project application.