简介:Anewmethodologyforprecisegeoiddeterminationwithfinestlocaldetailsbasedonellipsoidalapproximationispresented.Thismethodologyisformulatedthroughthe'fixed-freetwo-boundaryvalueproblem'basedontheobservableofthetypemodulusofgravityintensity,gravityaccelerationandgravitypotentialattheGPSpositionedstations,withsupportoftheknowngeoid'spotentialvalue,W0.
简介:Theartificialboundarymethodisappliedtosolvethree-dimensionalexteriorproblems.Twokindofrotatingellipsoidsarechosenastheartificialboundariesandtheexactarti-ficialboundaryconditionsarederivedexplicitlyintermsofaninfiniteseries.Thenthewell-posednessofthecoupledvariationalproblemisobtained.Itisfoundthaterroresti-matesderiveddependonthemeshsize,truncationtermandthelocationoftheartificialboundary.Threenumericalexamplesarepresentedtodemonstratetheeffectivenessandaccuracyoftheproposedmethod.