Abstract：Based on the CPI's repetition measurement GPS data built in Hefei to Fuzhou high-speed railway section ( HFZQ-8) , the survey technology and methods for level construction control network ( CPI) plane are mainly introduced. The acquired GPS original data of CPI are adjusted and processed by using the strict adjustment method, and every point of three dimension coordinates constraint adjustment results are calculated. The points are converted into the independent two-dimensional coordinate systems belong to the corresponding central meridian and geodetic height of a project surface. Then these coordinates and the plane coordinates offered by the design unit are compared, and two parameters of their absolute coordinates differences and the relative precision of the coordinate differences among adjacent point coordinates are analyzed. Finally, the stability of all CPI are analyzed and discussed, the conclusion of the repetition survey results and work instructions are drawn so as to ensure the plane survey precision and quality of projects to be correct. The research results have high reference value for similar projects.

Keyword：CPI repetition survey;baseline calculating;precision analysis;three dimensional constraint adjustment;stability analysis;