Compass Multi-frequency Combination Data Relative Positioning Research

Beidou satellite navigation system has B1, B2, B3three frequency bands, and thereare tri-band observations. This study is based on multi-frequency positioning principleof Beidou, and the author proposes to adopt Compass tri-band combinations toachieve relative positioning Compass tri-band combinations have the characteristicsof long wavelength observations, weak ionospheric delay and low observation noise.It also have some big advantages in the second order corrections of the ionosphere,cycle slip detection and repair, integer ambiguity solving, etc.. The main subject ofstudy are Launched from the following aspects:1. GNSS original data parsing code. According to Compass and GPS ICDdocuments, navigation message and the original code of Compass and GPS are parsedand transformed into the standard format RENIX.High-quality data can be obtainedby directly parsing the raw data, especially in the case of professional software cannot give a solution.2. Compass tri-band smart to select a combination of observations. According to thestandards of long wavelength observations, weak ionospheric delay and lowobservation noise, etc., Compass tri-band combinations observations are selected. Forthe clustering method previously used not ideal in the study combination observationsof GPS tri-band data, this paper proposes an incremental distance correction basedfuzzy C-Means algorithm and it can get the correct classification by adjusting thefactor and cluster center of the sample distance from the center effectively to obtain areasonable degree of membership; to avoid determine the number of clusters ofhuman irrationality, the author create distance-based clustering validity indexcorrection and automatically obtain best optimal number of clusters; based on the ideaof introducing an incremental, when data is increased based on the original data set,the new data are classified based on the original data set and without re re-calculation.The feasibility and reliability is proved by the matrix transformation method andtypical examples.3. Beidou tri-band combination observations cycle slip detection and repair. Firstly,the pseudo-range/phase method is applied to deal with Compass tri-bandcombination observations cycle slip detection and repair.Then Combination ofIonospheric residual method and Wide Lane M-W combination are also carried out on Compass tri-band combination observations the cycle slip detection and repair.Experiments show that the Combination of Ionospheric residual method and WideLane M-W combination has better cycle slip detection and repair capabilities than thepseudo-range/phase method. Finally, the Geometry-free method is introduced to dealwith tri-band combination observations cycle slip detection and repair.4. Compass Single Epoch Ambiguity Resolution.Integer Transformation andambiguity resolution progressively approach-CIR are applied to deal with Compasstri-band ambiguity,and acquire each ambiguity of B1, B2, B3three frequency bandjust by single epoch. Finally, their effects are compared.