A Study Of A Certain Number Of Questions In Construction Of Position Fundamental Geodetic Control Net

The construction of the foundation position control net is a complicated and huge project. It is very important for securing the ballistic surveying. To improve the accuracy of the foundation position control net and secure high quantities for the ballistic guided launch, this paper discusses the special problems and new survey technical means in the process of construction of the foundation position control net in detail. The main work and contributions are as follow.1. With respect to the construction of the control net, the characteristics of the GPS measurement and the contents of optimal design theoretically are discussed. The design of each basis and the various index sign of optimal design of GPS net's sketch structure strength are given.2. The principle of trigonometric leveling is introduced. The various reasons and futures of atmosphere refraction which affects its accuracy have been discussed. Based on these, this paper gives different models in different conditions, which can weaken the influence of the atmosphere refraction.3. A new theoretical model which is based on GPS method to determine the vertical deflection and earth azimuth angle to calculate the refraction coefficient by using real meteorological element is put forward,. It can solve the problem efficiently and accurately in theory.4. The influence of height errors on the guided missile accuracy has been analyzed. The height anomaly calculation model is introduced. And a comprehensive model which can fit the height anomaly by using GPS leveling is put forward. By using lots of examples, some calculation and comparison are performed.5. In recent years, in order to satisfy the demands of the war and guarantee the modernization of surveys, we need to densify the former control net urgently, and a lot of problems appeared. The RTK technical principle and how to found the position control net are discussed. The possibility that can densify the former position control net using RTK is discussed in detail.