Combined with survey experience, the author probed into the methods of setting up groundcontrol net with GPS and EDM lead for small hydropower projects based on the introduction of practice examples.
结合测量经验，探讨了用GPS与EDM导线建立小水电工程地面控制网的方法，并以实例加以介绍。
2
It discusses the influence of groundcontrol network, underground traverse survey, shaft orientation and gyroscopic orientation edge append-survey on breakthrough precision.