Abstract: InordertoimprovethegeometrystructureofGPSsatellitesandtheprecisionofGPS/pseudolitesintegratedrelativepositioning,fundamentaltheoriesbetweenGPSandpseudolitewerecompared.Then,thecorrespondingformulaswereillustrated,andthenecessityofthepseudoliteapplicationwasexplained.Afour-dimensionallocationmodelwasproposed,takingthedilutionofprecision(DOP)asthedependentvariableandtheparametersoftime,azimuthandelevationangleastheindependentvariables,andtheconcretestepstotheapplicationofthemodelwasgiven.Inaddition,aonestepadditionmethodofpseudolitewasgiventoimprovethemulti-stepone,andthepositiondilutionofprecision(PDOP)wastakenastheevaluationindex. Theresultsindicatethatthetwoadditionmannerscanrealizetheoptimalpseudolitelocationanddramaticallyimprovethereliabilityandefficiencyofthepseudolitelocation.And,thenewone-stepmethodissuperiortothemulti-stepone,especiallyforthecaseoftwopseudolitesaddition.ThenewmethodcanprovidemoreeffectivelocationschemeswiththePDOPdecreasingbyover1.0insomeunfavourableareas.

Key words: GlobalPositioningSystem, Pseudolite, Dilutionofprecision, Optimallocation, Integratedpositioning, Relativepositioning