简介:Anautomaticdependentsurveillancebroadcast(ADS-B)systemhasserioussecurityproblems,andthedatacanbespoofedduringbroadcastingprecisepositioninformationofaircraft.AsolutionoftheADS-Bsystemdataauthenticationbasedontheellipticcurvecipher(ECC)andX.509certificateisproposed.ItcanavoidthekeydistributionproblembyusingthesymmetrickeyalgorithmandpreventtheADS-Bdatafrombeingspoofedthoroughly.ExperimentaltestresultsshowthatthesolutionisvalidandappropriateinADS-Buniversalaccesstransceiver(UAT)mode.
简介:文章针对株洲县堂市乡某部分区域高分辨率影像,采用eCognition的多尺度分割和面向对象的最邻近法对影像进行分类,同时与ENVI5.3软件平台下的最大似然法分类结果进行了对比分析,并以野外验证后的目视解译为基准进行精度评价。结果表明:基于eCognition平台下的面向对象的分类方法避免了传统分类结果噪声严重、精度低的缺陷,其总体分类精度为80%,Kappa系数为0.7397,比传统分类结果精度高,比目视解译效率高。