资源描述：
《Smoothness_criteria_in_surface_wave_tomography.pdf》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。
1、Geophys.J.Int.(1990)102,63-72SmoothnesscriteriainsurfacewavetomographyT.B.YanovskayaandP.G.DitmarInstituteofPhysics,LeningradUniversity,Petrodvoretz,Leningrad198904,USSRAccepted1989December19.Received1989December10;inoriginalform1988October14SUMMARYWediscussanddevelopfurtherthemethodsofsurfacew
2、avetomographyintheframeofthegeometricrayapproximation.Thegeneralapproachfordeterminingthelateralphaseorgroupvelocitydistribution,whichisastandard2-Dtomographyproblem,involveslinearization,representationoftheunknownfunctionasaseriesinsomebasisfunctions,andevaluationofthecoefficientsbythemethodso
3、flinearalgebra.Ifthewavepathscovertheareaunderinvestigationnon-uniformly,thebasisfunctionsshouldnotbechosenapriori,butconstructedproceedingfromthepatternofpaths.Differentcriteriaforconstructingthebasisfunctionsarecompared,andarelationbetweenthemisconsidered.Amorepreferableapproachisjointinterpr
4、etationofphaseandgroupvelocitydatafordifferentperiods,becauseitallowstheinformationaboutphasevelocityvariationstobeenlargedduetotheuseofthegroupvelocitydata.Boththephaseandgrouptraveltimesarerepresentedaslinearfunctionalsoftheunknownphaseslownesscorrections.Aspecificformofthedatakernelsallowsth
5、ebasisfunctionstoberepresentedasaproductoftwofunctions,onedependingonthehorizontalcoordinates,andtheotheronfrequency.Keywords:basisfunctions,phaseandgroupvelocities,surfacewaves,tomography.variationsaredecoupled(thisassumptionispracticallyINTRODUCTIONfulfilled).Suchatwo-stepapproachismoreprefer
6、ablethanPhaseorgroupsurfacewavevelocitiesobservedalongadirect3-Dinversion,becauseinthiscasethecalculationsdifferentpathsarewidelyusedtostudylateralvariationsaremuchsimpler.Thusthe3-Dinverseproblemusingandanisotropyoflithosphericstructure(seeforexamplesurfacewavedatamaybeseparatedintotwoindepend
7、entSat0&Santo1969;Avetisyan&Yanovskaya1973;problems:2-DinversionforphaseorgroupvelocitiesforaBerteussen,Levshin&Ratnikova1982;Nakanishi&iixedperiod,resultinginlateralvariationsofthesevelocitiesAnderson1982,1983,1984;Yanovskaya1982
