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Study On Data Quality Assessment And Integrity Monitoring Of GPS/BDS

Posted on:2015-11-11Degree:MasterType:Thesis
Country:ChinaCandidate:L H FanFull Text:PDF
GTID:2180330422485453Subject:Geodesy and Survey Engineering
Abstract/Summary:PDF Full Text Request
With the widely application of satellite navigation system such as GPS and BDS, therequirements for its performance are also increasing. The mainly observations of navigationsystem including ranging code observation, carrier phase observation and navigation data et al.Carrier phase observations are often used in high-precision deformation monitoring, precisesurveying and positioning, while the accurate cycle slip detection and repair is critical toobtain high-precision positioning results. In addition, ranging code and broadcast ephemerisare widely used in real-time navigation positioning (such as aviation navigation). Theintegrity and availability of navigation system involves more attention than accuracy in thenavigation application of safety. So it requires the accurate assessment of GNSS systemperformance. Therefore, this paper analysis the following contents: the cycle slip detectionand repair of carrier phase observation, multipath error calculating and analysis in observationdata quality checking, accuracy assessment of broadcast ephemeris, and the systemconstellation availability.The main research and achievement of this paper are as follows:(1) On the problem of cycle slip detection and repair in carrier phase observations, acombination of MW and STPIR observations is analyzed. The result shows that: STPIRcombination eliminates the high-order of ionospheric delay, can detect cycle slip better. Thecombination of MW and STPIR observation could complement the detecting insensitivitybetween each other. Then it can detect and repair cycle slip thoroughly.(2) On the problem of observation data quality checking, the principle, advantage anddisadvantage of quality checking using TEQC software are analyzed. On account ofenvironment quality reflected by multipath error, the computing method is analyzed. On themulti-system observations from a multi-mode station, the multipath error of GPS and BDSobservations are compared and analyzed.(3) As broadcast ephemeris is still used in real-time navigation. For the accuracy ofspatial signal, the calculation method of URE parameters of navigation satellite is analyzed, and then URE parameters of GPS satellites and BDS satellites in different orbit height arecalculated. Finally a comparative analysis of GPS and BDS satellite orbit and clock erroraccuracy in2012is conducted by using afterwards precise ephemeris. Results show that: Theaverage error in orbit URE of GPS satellite is about1m, the average error of satellite clock isabout6ns. While the average error in orbit URE of BDS satellite is about12m, the averageerror of satellite clock is about25ns.(4) In the navigation of civil aviation, it pays more attention to the integrity andavailability of GNSS. On the issues of system constellation availability, the systemconstellation availability of GPS and BDS in China region is analyzed based on the leastsquare residual method. Results show that: The availability of BDS in China area is graduallyimproved with the increase of satellite, especially in the middle east area. After theaccomplishment of BDS space constellation, its availability will be improved.
Keywords/Search Tags:cycle slip, broadcast ephemeris, integrity, URE, RAIM
PDF Full Text Request
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