Research On Measuring The Attitude Of The Carrier Based On Differential Technology

Satellite navigating equipments were first designed for providing measuring of precise distances and position in a global context, but with the development of technology, the satellite navigating based attitude measurement system has gradually replaced the traditional inertial device based measurement system or fusion it to build an integrated system to produce swifter results of attitude measuring. Satellite navigation equipment was originally developed for military uses, and then it opens to the public which can be widely used in aviation,aerospace, marine and land vehicle navigation, etc. In order to get a higher precision of positioning and relative pose computing under present satellite conditions, the research in this thesis on satellite navigating system based attitude measurement method has a strong practical application of significance.The existing national satellite navigation system has been introduced in this thesis,among them GPS is chosen to bring the environment to study and analyze the methods of attitude measurement. As the attitude measurement platform with single baseline could only measure 2D attitude angle, and the attitude measurement of 3D angle could be solved by more than two baselines which needs three antennas at least. To validate the practical application of significance in this thesis uses an attitude measurement platform with three non-collinear antennas to build the simulation research environment.This thesis uses the carrier phase double difference model as a calculating model in the attitude measurement algorithm, the most difficulty part in calculating of carrier phase difference is to solve the integer number of the carrier phase, which is regard as the integer ambiguity of carrier phase. This thesis compares two famous determinations of ambiguity algorithm; one is based on geometric model, another is based on the improved LAMBDA algorithm. After that,to reach a low level of search space and accelerate calculating rate, an optimization method to adjust the sequence in the process of iterative calculation is introduced in this thesis, and then modeling the carrier phase double difference model for linearization.In this thesis, RENIX format file is used as attitude measurement experiment data to build a MATLAB based attitude measuring calculating platform. The initial attitude angle, the baseline length and its deviation could be solved out by the point positioning result through each antenna. Using the least squares estimate to solve the accurate attitude parameters,baseline length and deviation of the baseline.