The Algorithms And Software Development Of BDS/GPS Baseline Solution

Beidou satellite navigation system(BDS) in China has the ability of local-basedservices in the Asia-Pacific region at the end of2012. With the modernization of GPSand the development of GLONASS、Galileo and BDS in the future, the focus of ourresearch is that how to make full use of multiple satellite system and their three or evenmore carrier observations. Based on the theory of multiple satellite system processing,our main research is focused on the data preprocessing, dual system combination, cycleslip detecting and repairing, ambiguity resolution and the baseline solution. Furthermore, we take some experiments to verify the feasibility of these theories and methods,and finally write a baseline solution software.Firstly, this paper analyzes the error model of single point positioning and baselinesolution, and emphatically analyzes the multipath effect. Besides the multipathindicators of mp1and mp2, this paper proposes a new indicator named mpc based ondual-frequency observation. The new indicator can get a comprehensive reflection ofmp1, mp2and avoid the requirement of different sampling interval on the smoothwindow. By a test of different type of orbit satellite, we can make a conclusion thatBDS’s GEO and IGSO satellite has a large multipath than MEO satellite. In terms ofcycle slip detecting and repairing, this paper give an introduction of the commonmethods of cycle slip detecting and repairing and mainly analyzes the wide lane andextra wide-lane TurboEdit method. By a test of triple-frequency data of BDS, we findthe extra wide-lane TurboEdit method can detect and repair any size of cycle slip oneach frequency at the same time. In terms of ambiguity resolution, according to thecharacteristics of baseline solution, this paper focuses on the analysis of the currentwidely used method, such as LAMBDA method, wide lane-narrow lane method andTCAR method, and then we propose a new ambiguity resolution method using the threecarrier observation combination. This new method is consistent with the LAMBDAmethod in terms of accuracy and success rate of ambiguity resolution, but its operatingefficiency is much higher than the LAMBDA method.In this paper, we mainly research the algorithms of baseline solution and thenachieve a dual system integrated positioning by BDS and GPS. By a test of dual-frequency data of BDS and GPS, we find that the RMS of a6.4m short baselinecould reach mm level. At the same time, we can find that the combined system has ahigher accuracy and reliability than the single system. Another test is a medium baselineof24.2km, and the BDS performs a cm level solution. Finally we test a long baseline of181.0km and the RMS of BDS can reach dm level. Based on the theoretical andmodeling algorithm of BDS/GPS baseline solution, this paper developed a baselinesolution software which can process BDS/GPS system or dual system data. By someexamples with measured data of BDS/GPS system, we can get some useful conclusionswhich provide basis for enhancing and improving BDS and depth research on baselinesolution of BDS/GPS combined system.