Optical Trigonometric Leveling In High-speed Rail CPⅢ Measurement

Nowadays, with the rapid development of high speed railway, it is necessary to establish a set of high-precision control network which controls the track installation, operation and maintenance later. According to found a set of complete, efficient and accurate measuring system is the necessary security for the engineering construction and operation of the project. So the CPⅢ Control Network occupies a very important position in the high speed railway.When we measure the CPⅢ Trigonometric Leveling, there are many factors which can affect the data of precision and the height difference, such as atmospheric refraction, the earth curvature, instrument error and the accuracy of adjustment methods and so on. It is necessary to select a rational and correct and practicable measurement method, which can improve data accuracy and reduces the labor intensity as well.Through arguing and searching the method about the reasonable combination of the CPⅢ Trigonometric Leveling data, improved the data accuracy of CPIII Trigonometric Leveling by adopting a suitable method. The dissertation also attempted to realize the communication of integrating of double nets about horizontal control network and elevation control network. Data acquisition of the paper is divided into three parts.-(1) On data collection: The acquisition of leveling data uses Leica DNA03Electronic Level. The acquisition of trigonometric leveling date uses T1201Total Station.(2) On data processing aspect: According to the characteristic of triangulated height measurement data and a large number of documents, using the Midway Method for CPⅢ Trigonometric Leveling can be good offset and weaken errors, at the same time it can ensure the stability of the network type collocate with the leveling data.(3) On data Adjustment method:The elimination of gross error and the adjustment methods refer to the chapter of CPⅢ Trigonometric Leveling in the book Specifications For Survey Engineering Of High Speed Railway. The thesis centre on the idea of improving CPⅢ Trigonometric Leveling network type by the Hybrid network type which combined CPⅢ Trigonometric Leveling with Level Measurement, and finally the Adjustment of Data was calculated based on the Hybrid network type.The last chapter of the paper analysed the gaps between the three kinds of CPⅢ Trigonometric Leveling and the Leveling Measurement, at the same time, pointed out advantages and shortcomings.