Combination GPS Elevation with Precision Trigonometric Leveling Method in Tunnel Control Application
Shi Kun · Journal of Navigation and Positioning · 2013
In case of elevation data can not satisfy surveying work when a vertical control survey is on processing,which usually attribute to the destruction of height control points,the GPS control network should be established firstly.As the component of the control network,GPS control points shall include all of the available and steady height points.Starting from a known height point the EDM trigonometric leveling can be measured;and the route eventually become a closed loop which contains all GPS control points.The elevation anomaly could be supposed to be a constant in a small area thus the results of trigonometric leveling can be checked in real time by compared with the high-accuracy WGS84 geodetic height data.The practice shows that measuring accuracy and measuring efficiency of this method can meet requirements of the mountain engineering measurement.