简介:Syntheticapertureradarinterferometry(InSAR)hasbeenusedasaninnovativetechniquefordigitalelevationmodel(DEM)andtopographicmapgeneration.Inthispaper,externalDEMsareusedforInSARDEMgenerationtoreducetheerrorsindataprocessing.TheDEMsgeneratedfromrepeat-passInSARarecompared.Forsteepslopesandseverechangesintopography,phaseunwrappingqualitycanbeimprovedbysubtractingthephasecalculatedfromanexternalDEM.ItisaffirmativethattheabsoluteheightaccuracyoftheInSARDEMisimprovedbyusingexternalDEM.Thedataprocessingwasundertakenwithouttheuseofgroundcontrolpointsandothermanualoperation.