一种改进的GPSGLONASS组合精密单点定位算法在露天矿区测量中的应用英文.docx

Trans. Nonferrous Met. Soc. China 24(2014)1547?1553Modified algorithm of combined GPS/GLONASS precise point positioningforapplications in open-pitminesChang-sheng CAI, Xiao-min LUO, Jian-junZHUSchoolofGeosciencesandInfo-Physics,CentralSouthUniversity,Changsha410083,ChinaReceived 10 July 2013; accepted 17 January2014Abstract: A modified algorithm of combined GPS/GLONASS precise point positioning (GG-PPP) was developed by decreasingthenumberofunknownstobeestimatedsothataccuratepositionsolutionscanbeachievedinthecaseoflessnumberofvisiblesatellites.ThesystemtimedifferencebetweenGPSandGLONASS(STDGG)andzenithtroposphericdelay(ZTD)valueswere firstly estimated in an open sky condition using the traditional GG-PPP algorithm. Then, they were used as a priori known valuesinthemodifiedalgorithminsteadofestimatingthemasunknowns.TheproposedalgorithmwastestedusingobservationscollectedatBJFSstationinasimulatedopen-pitmineenvironment.Theresultsshowthatthepositionfilterconvergesmuchfastertoastablevalueinallthreecoordinatecomponentsusingthemodifiedalgorithmthanusingthetraditionalalgorithm.Themodifiedalgorithmachieveshigherpositioningaccuracyaswell.Theaccuracyimprovementinthehorizontaldirectionandverticaldirectionreaches69% and 95% at a satellite elevation mask angle of 50°,respectively.Keywords:GPS;GLONASS;precisepointpositioning;elevationmaskangle;open-pitmineIntroductionPrecise point positioning (PPP) is a techniquethatuses dual-frequency carrier phase observations fromasingle receiver along with precise satellite orbit andclockproductstoachieveanaccuracyofdecimetertocentimeter level [1,2]. In the past, the PPP techniquewasmainly implemented using GPS-only observations.Butfor such a satellite-based positioning technique,theaccuracy, availability and reliability of positionsolutionsare largely dependent on the number of visiblesatellites.In open-pit mines, the number of tracked GPS satellitesis often insufficient to obtain a high-accuracypositioningsolution. With the revitalization a