数模英文848篇1989-2018美赛建模2018年美赛o奖a77845-mhpm and msrsm simulation and modeling of multi-hop hf radio propagation.pdf

TeamControlNumber Forofficeu nly 77845 Forofficeu nly T1 F1 T2 F2 T3 ProblemChosen F3 T4 A F4 2018 MCM/ICM SummarySheet MHPMandMSRSM:SimulationandModelingof Multi-hopHFRadioPropagation Summary Based on the properties of the ionosphere and some l of physics, we h e established a complete mathematical model named MHPM that can well simulate the refraction and reflection in the propagation of multi-hop high- frequency radio w es. MHPM can also simulate the distribution of electron densityandrefractiveindexintheionospherealongaltitude.Theattenuationof energy in the D layer ionosphere, the free-space path loss and the energy loss while reflecting off the ground or sea surface determine the energy loss during radio w e propagation, based on which, our model can successfully simulatethelossofenergyduringthepropagationofradiow e. UsingMHPM,wecomparethedifferenteffectsofthecalmandturbulent seasurfaceontheenergydissipationofradiow es,andcalculatethemax- imumpropagationdistanceandthe umhopnumberofseveral cases (differentfrequenciesanddifferentgrazingangles).Wealsoanalyzethein- fluenceofgrazingangle,frequencyandthewindspeedneartheseasurface ontherefractioneffectofroughseasurface.TheMHPMcanalsobeapplied toground-reflectionsituationsverywell,andwefindtheenergydissipationof radiow es in ground-reflectioncaseincreasesrapidly withtheincrea f elevationstandarddeviation. We propo