Passive jamming is believed to have very good potential in countermeasure community.In this paper,a passive angular blinking jamming method based on electronically controlled corner reflectors is proposed.The amplitud...Passive jamming is believed to have very good potential in countermeasure community.In this paper,a passive angular blinking jamming method based on electronically controlled corner reflectors is proposed.The amplitude of the incident wave can be modulated by switching the corner reflector between the penetration state and the reflection state,and the ensemble of multiple corner reflectors with towing rope can result in complex angle decoying effects.Dependency of the decoying effect on corner reflectors’radar cross section and positions are analyzed and simulated.Results show that the angle measured by a monopulse radar can be significantly interfered by this method while the automatic tracking is employed.展开更多
In this study,Differential Interferometric Synthetic Aperture Radar Interferometry(DInSAR)of artificial Corner Reflectors(CRs)were validated in the area of fast and nonlinear deformation gradient caused by active coal...In this study,Differential Interferometric Synthetic Aperture Radar Interferometry(DInSAR)of artificial Corner Reflectors(CRs)were validated in the area of fast and nonlinear deformation gradient caused by active coal longwall exploitation.Three Sentinel-1 datasets were processed using conventional DInSAR,Persistent Scatterer Interferometry(PSI),and Small BAseline Subset methods implemented in ENVI SARscape™.For evaluation,leveling and Global Navigation Satellite System(GNSS)measurements were used.Considering the challenge of snow cover,the removal of all winter images was not a successful strategy due to the long temporal baseline and strong movement,which cause phase unwrapping problems and underestimate the real deformation.The results indicate that only conventional DInSAR and SBAS with low network redundancy allow us to capture maximal deformation gradient and the root mean square error calculated between the CRs and the ground truth is on the level of 2–3 cm for the vertical and easting deformation component,respectively.For the small deformation gradient represented by the permanent GNSS station(4 cm/year),all SBAS techniques appeared to be more accurate than DInSAR,which corresponds to higher redundancy and better removal of the atmospheric signal.In contrast,DInSAR results allowed to capture information about two subsidence basins,which was not possible with SBAS and PSI approaches.展开更多
角反射器是一种宽角域的常见无源干扰设备,常被用于保护关键目标.但传统金属角反射器特性固定,需借助新型电磁材料实现角反射器的特性优化.有源频率选择表面(adaptive frequency selective surface,AFSS)是在单元间加载一系列可变有源...角反射器是一种宽角域的常见无源干扰设备,常被用于保护关键目标.但传统金属角反射器特性固定,需借助新型电磁材料实现角反射器的特性优化.有源频率选择表面(adaptive frequency selective surface,AFSS)是在单元间加载一系列可变有源器件而构成的具有可调电磁特性的新型结构.为拓展角反射器的适用范围、分析电磁材料角反射器的散射特性以更好地保护关键目标,本文设计了一种基于单面AFSS的电控角反射器,并仿真计算分析了该电控角反射器的散射特性.仿真结果表明设计的电控角反射器的散射特性可灵活调控,即不同偏置电流下AFSS单元可对入射电磁波能量产生不同反射效果;同时验证了该电磁调控角反射器的宽角域特性,其调控角域在方位向、俯仰向均大于60°,实现了基于无源散射体的宽角域实时调控效果.相较于传统角反射器和平面电磁材料,所设计电控角反射器兼具实时调控性和宽角域特性,拓展了角反射器的应用场景和适用范围.展开更多
基金supported by the Equipment Pre-research Project(GK202002A020068)。
文摘Passive jamming is believed to have very good potential in countermeasure community.In this paper,a passive angular blinking jamming method based on electronically controlled corner reflectors is proposed.The amplitude of the incident wave can be modulated by switching the corner reflector between the penetration state and the reflection state,and the ensemble of multiple corner reflectors with towing rope can result in complex angle decoying effects.Dependency of the decoying effect on corner reflectors’radar cross section and positions are analyzed and simulated.Results show that the angle measured by a monopulse radar can be significantly interfered by this method while the automatic tracking is employed.
基金The research infrastructure that has been used for computation purposes was created within the project EPOS-PL(POIR.04.02.00-14-A003/16)EPOS-PL+(POIR.04.02.00-00-C005/19-00)European Plate Observing System,funded by the Operational Programme Smart Growth 2014-2020,Priority IV:Increasing the research potential,Action 4.2:Development of modern research infrastructure of the science sector and co-financed by the European Regional Development Fund.
文摘In this study,Differential Interferometric Synthetic Aperture Radar Interferometry(DInSAR)of artificial Corner Reflectors(CRs)were validated in the area of fast and nonlinear deformation gradient caused by active coal longwall exploitation.Three Sentinel-1 datasets were processed using conventional DInSAR,Persistent Scatterer Interferometry(PSI),and Small BAseline Subset methods implemented in ENVI SARscape™.For evaluation,leveling and Global Navigation Satellite System(GNSS)measurements were used.Considering the challenge of snow cover,the removal of all winter images was not a successful strategy due to the long temporal baseline and strong movement,which cause phase unwrapping problems and underestimate the real deformation.The results indicate that only conventional DInSAR and SBAS with low network redundancy allow us to capture maximal deformation gradient and the root mean square error calculated between the CRs and the ground truth is on the level of 2–3 cm for the vertical and easting deformation component,respectively.For the small deformation gradient represented by the permanent GNSS station(4 cm/year),all SBAS techniques appeared to be more accurate than DInSAR,which corresponds to higher redundancy and better removal of the atmospheric signal.In contrast,DInSAR results allowed to capture information about two subsidence basins,which was not possible with SBAS and PSI approaches.
文摘角反射器是一种宽角域的常见无源干扰设备,常被用于保护关键目标.但传统金属角反射器特性固定,需借助新型电磁材料实现角反射器的特性优化.有源频率选择表面(adaptive frequency selective surface,AFSS)是在单元间加载一系列可变有源器件而构成的具有可调电磁特性的新型结构.为拓展角反射器的适用范围、分析电磁材料角反射器的散射特性以更好地保护关键目标,本文设计了一种基于单面AFSS的电控角反射器,并仿真计算分析了该电控角反射器的散射特性.仿真结果表明设计的电控角反射器的散射特性可灵活调控,即不同偏置电流下AFSS单元可对入射电磁波能量产生不同反射效果;同时验证了该电磁调控角反射器的宽角域特性,其调控角域在方位向、俯仰向均大于60°,实现了基于无源散射体的宽角域实时调控效果.相较于传统角反射器和平面电磁材料,所设计电控角反射器兼具实时调控性和宽角域特性,拓展了角反射器的应用场景和适用范围.
