Establishment of Precise Three-dimensional Coordinate Control Network in Field Large-space Measurement

Global measurement and precision control are the basis of precision measurement in large space,determine the applicability and performance of overall measurement.In order to improve overall spatial measurement accuracy,while solving the problem of orientation and scale,high-precision measuring control network must be laid in the global space.As an important representative of geometric measurement,three-dimensional coordinate is the most direct way and the strongest constraint in establishment of the measurement control network.In order to establish precise coordinate control network,laser tracker is used to measure three-dimensional coordinate of global points by multi-station,then orientations of all stations are figured out by singular value decomposition algorithm,and tracker angle measurement error is optimized by making the high-precision length measurement as a constraint to improve accuracy of the coordinate control network.This method is applied to shape measurement of aircraft wing surface,it can realize the combination of tracker global control and terminal photogrammetry,the result of comparing with distances between global control points in several stations is demonstrated that the control network can improve the field measuring accuracy and reliability.