简介:日前,信息产业部无线电管理局就进一步加强450~470MHz频段的管理,保障无线电频谱资源的合理开发发出通知。
简介:Duetothegoodperformanceoftrackinglowelevationtargetascomparedtomicrowaveandthesuperiorityinpenetratingsmoke,dust,fog,anddrysnowascomparedtoinfrared,aKuandKadualbandexperimentalradarwasdesignedanddeveloped.ThisKuandKadualbandexperimentalradarisanarnplitute-comparisonmonopulsetrackingandguidingradar.Theconstitutionandparametersofthisradarisdescribedinparagraph2.Paragraph3dealswithtwoexperimentsfortestingthetrackingperformancesagainstlowelevationtarget,andgivestheimportantresults.BothKuandKabandhavehightrackingprecisionwhentheytrackhighelevationtargets,whileKabandhasmuchbettertrackingperformancethanKubandwhentheytracklowelevationtargets.Kabandcantrackahelicopter,whoseradarcrosssectionisabout6squaremeters,at40m,20m,10m,andeven5mabovesea.Kubandcanonlytrackthesamehelicopterat160mandhigherabovesea.