Research on the Total Station Trigonometric Leveling Using Midway Method Replaces Three/Four Grade Leveling

In order to improve the precise of trigonometric leveling, analysis of the midway method by theoretical analysis and experiment. A formula is derived to calculate the elevation difference and the mean square error base on the error propagation law. The result of research includes: the midway method of total station trigonometric leveling is simple operated , it can replaces the three/four grade leveling through a variety of correction under certain conditions.