针对非均匀地面参数引起的短波测向误差问题,导出了含有地面参数的测向阵列流形模型,给出了水平极化和垂直极化两种圆形阵列流形的具体表达式,并利用多重信号分类(multiple signal classification,MUSIC)方法对地面参数不均匀性导致的...针对非均匀地面参数引起的短波测向误差问题,导出了含有地面参数的测向阵列流形模型,给出了水平极化和垂直极化两种圆形阵列流形的具体表达式,并利用多重信号分类(multiple signal classification,MUSIC)方法对地面参数不均匀性导致的两种阵列测向误差进行了仿真.仿真结果表明:对沿着地面参数不均匀区分界方向的来波信号,方位角测向明显存在较大的测向误差;在低电导率的非均匀地面,地面相对介电常数的变化对方位角测向误差有着显著影响,可达到2°~3°;非均匀地面参数对垂直极化阵列测向误差要比水平极化阵列高出1°~2°.因此在短波固定测向站建设时,尽可能选址高电导率区域,并铺设地网改善天线场地的均匀性,来消除非均匀地面参数变化引起的测向误差.展开更多
A M3. 4 seismic event occurred in the Punggye-ri nuclear test site,D. P. R Korea at 16∶29 p.m. on September 23,2017. We analyzed the waveforms of this event recorded by the China Earthquake Networks Center. In conclu...A M3. 4 seismic event occurred in the Punggye-ri nuclear test site,D. P. R Korea at 16∶29 p.m. on September 23,2017. We analyzed the waveforms of this event recorded by the China Earthquake Networks Center. In conclusion,this event is complex,including an explosion with a successive earthquake. Although the beginning of the event is an explosion,fault dislocation plays the main role in the event.展开更多
文摘针对非均匀地面参数引起的短波测向误差问题,导出了含有地面参数的测向阵列流形模型,给出了水平极化和垂直极化两种圆形阵列流形的具体表达式,并利用多重信号分类(multiple signal classification,MUSIC)方法对地面参数不均匀性导致的两种阵列测向误差进行了仿真.仿真结果表明:对沿着地面参数不均匀区分界方向的来波信号,方位角测向明显存在较大的测向误差;在低电导率的非均匀地面,地面相对介电常数的变化对方位角测向误差有着显著影响,可达到2°~3°;非均匀地面参数对垂直极化阵列测向误差要比水平极化阵列高出1°~2°.因此在短波固定测向站建设时,尽可能选址高电导率区域,并铺设地网改善天线场地的均匀性,来消除非均匀地面参数变化引起的测向误差.
基金sponsored by the Earthquake Research Project of China Earthquake Administration:Study on Magnitude Determination Method in Auto-report and Development of the Real-time Monitoring Software (201508012)
文摘A M3. 4 seismic event occurred in the Punggye-ri nuclear test site,D. P. R Korea at 16∶29 p.m. on September 23,2017. We analyzed the waveforms of this event recorded by the China Earthquake Networks Center. In conclusion,this event is complex,including an explosion with a successive earthquake. Although the beginning of the event is an explosion,fault dislocation plays the main role in the event.
