Polarization singularities,which emerge from the incoherent superposition of two vector electric fields with the same frequency,and their evolution in free space are studied analytically and illustrated by numerical e...Polarization singularities,which emerge from the incoherent superposition of two vector electric fields with the same frequency,and their evolution in free space are studied analytically and illustrated by numerical examples.It is shown that there exist C-points,L-lines,in particular,C-lines in incoherently superimposed two-dimensional wavefields.Usually,the C-lines are unstable and disappear during the free-space propagation.The motion,pair creation-annihilation process of the emergent C-points,as well as the distortion of the L-lines may take place,and the degree of polarization of the emergent C-points varies upon propagation and may be less than 1.展开更多
通过并网整合、站点加密、差站迁建和软件升级,建立网形更优、覆盖更广的新一代昆明市卫星定位综合服务系统(Kunming Continuously Operating Reference Stations,KMCORS)。在KMCORS的NRTK(Network Real Time Kinematic,网络实时动态定...通过并网整合、站点加密、差站迁建和软件升级,建立网形更优、覆盖更广的新一代昆明市卫星定位综合服务系统(Kunming Continuously Operating Reference Stations,KMCORS)。在KMCORS的NRTK(Network Real Time Kinematic,网络实时动态定位技术)性能测试中,于C级测试点CD(长地)和DY(大营)处发现定位异常问题,为分析其原因,进行测试点原成果检核和对流层异常探测工作。结果表明,DY点位因施工发生偏移,其修正坐标符合NRTK定位结果;CD点对流层状态异常,与临近CORS站存在显著差异,致使其对流层延迟未能有效订正,最终造成较大的高程误差。今后,将收集CD附近区域的观测数据,用以精化KMCORS现有的对流层模型。展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No. 10874125)
文摘Polarization singularities,which emerge from the incoherent superposition of two vector electric fields with the same frequency,and their evolution in free space are studied analytically and illustrated by numerical examples.It is shown that there exist C-points,L-lines,in particular,C-lines in incoherently superimposed two-dimensional wavefields.Usually,the C-lines are unstable and disappear during the free-space propagation.The motion,pair creation-annihilation process of the emergent C-points,as well as the distortion of the L-lines may take place,and the degree of polarization of the emergent C-points varies upon propagation and may be less than 1.
文摘通过并网整合、站点加密、差站迁建和软件升级,建立网形更优、覆盖更广的新一代昆明市卫星定位综合服务系统(Kunming Continuously Operating Reference Stations,KMCORS)。在KMCORS的NRTK(Network Real Time Kinematic,网络实时动态定位技术)性能测试中,于C级测试点CD(长地)和DY(大营)处发现定位异常问题,为分析其原因,进行测试点原成果检核和对流层异常探测工作。结果表明,DY点位因施工发生偏移,其修正坐标符合NRTK定位结果;CD点对流层状态异常,与临近CORS站存在显著差异,致使其对流层延迟未能有效订正,最终造成较大的高程误差。今后,将收集CD附近区域的观测数据,用以精化KMCORS现有的对流层模型。
