Cycle Slip Detection And Correction Of COMPASS Based On Wavelet Transform

Satellite navigation system is an important spatial information infrastructure. Ourcountry pays high attention to the construct of satellite navigation system, trying to exploreand develop. COMPASS will be the global satellite navigation system researched only by ourcontry, which is being implemented with self-development and independent working, andCOMPASS has been successfully used in mapping, telecom, transportation, disaster relief,public satety and other areas, producing significant economic and social benefits. With theexpanding of COMPASS applications, people have more and more demand for COMPASS,so requires to continue developing the technologies and applications of COMPASS.The applications of carrier phase measurement is always paid comprehensive attention insatellite navigation system. However, cycle slip is a peculiar problem of carrier phasemeasurement technology. The existance of cycle slip brings influences to the veracity ofcalculating integer ambiguity and the precision of positioning or measuring attitude andvelocity by the signal of COMPASS. There are some methods of calculating integerambiguity that have already ingnored the existance of cycle slip, but the methods can’tcalculate accurately, and make real-time low. Detecting and repairing for cycle slip remain aessential work in satellite positioning and navigation with the high precision. The thesis takesdouble difference carrier phase as cycle slip examination quantities, then detects the epochwhen the cycle slip occures, calculates the size of cycle slip by combining the method ofpolynomial fittng and kalman filte, at last repairs the cycle slip.Firstly, the thesis systemmatically expatiates COMPASS satellite navigation system, thesignal character and basic survey parameter of COMPASS satellite navigation, and any errorsprobably existed in the observation of COMPASS, then summarizes and classifies the sourceof the errors, and puts forward several methods for the errors processing.Secondly, it generalizes the definition of cycle slip, analyzes the reasons and influencethe cycle slip produces, expatiates the strcture principle of cycle slip examination quantitiesand several commonly used cycle slip examination quantities, then compares and analyzesthem, summarizes their own excellence and defect, and selects double difference carrier phaseas cycle slip examination quantities in the thesis.Then, based on the detection and repair GPS cycle slip, studies and analyzes the highermode method of difference, wavelet transform, polynomial fitting, and kalman filter, which fitdetection and repair COMPASS navigation signal cycle slip, summarizes their principle and the process of detecting and repairing cycle slip, and through the analysis above proposesthird level combination method based on wavelet transform, that detects cycle slip by wavelettransform and repairs by combining polynomial fitting and kalman filter. It expatiates theprinciple and the theoretical basis of the proposed method, compiles the program of all themethods above, and verifies their capacity of detection and repair cycle slip by practial case. Itsummarize advantage and limitation of the methods above, and verifies the validity of theproposed third level combination method in the thesis. The simulation shows the method candetect the epoch of occuring cycle slip and repair it accurately, and the proposed methodexcels the others.At last, it summarizes the full text, generalizes the work and achievement done by thethesis, and points out the direction of the detection and repair COMPASS signal cycle slip.