随着无线电技术的发展,射频干扰(radio frequency interference,RFI)对射电天文观测的影响越来越大,尤其是周期性RFI对天文观测的影响越来越显著。本文围绕宽带、高时间分辨率频谱数据,采用阈值计算、噪声通道过滤、快速傅里叶变换、周...随着无线电技术的发展,射频干扰(radio frequency interference,RFI)对射电天文观测的影响越来越大,尤其是周期性RFI对天文观测的影响越来越显著。本文围绕宽带、高时间分辨率频谱数据,采用阈值计算、噪声通道过滤、快速傅里叶变换、周期计算、通道合并、来源分析和模板库建立等步骤,提出一种面向宽带频谱序列的周期RFI统计方法。将该方法应用于新疆天文台南山观测站26 m射电望远镜(Nan Shan 26 m Radio Telescope,NSRT)脉冲星观测终端数据,有效地检测并提取出了频谱序列中的周期性RFI,可为进一步电磁干扰缓解提供数据支撑。展开更多
Synthetic aperture radar(SAR)is a high-resolution two-dimensional imaging radar.However,during the imaging process,SAR is susceptible to intentional and unintentional interference,with radio frequency inter⁃ference(RF...Synthetic aperture radar(SAR)is a high-resolution two-dimensional imaging radar.However,during the imaging process,SAR is susceptible to intentional and unintentional interference,with radio frequency inter⁃ference(RFI)being the most common type,leading to a severe degradation in image quality.To address the above problem,numerous algorithms have been proposed.Although inpainting networks have achieved excellent results,their generalization is unclear.Whether they still work effectively in cross-sensor experiments needs fur⁃ther verification.Through the time-frequency analysis to interference signals,this work finds that interference holds domain invariant features between different sensors.Therefore,this work reconstructs the loss function and extracts the domain invariant features to improve its generalization.Ultimately,this work proposes a SAR RFI suppression method based on domain invariant features,and embeds the RFI suppression into SAR imaging pro⁃cess.Compared to traditional notch filtering methods,the proposed approach not only removes interference but also effectively preserves strong scattering targets.Compared to PISNet,our method can extract domain invariant features and hold better generalization ability,and even in the cross-sensor experiments,our method can still achieve excellent results.In cross-sensor experiments,training data and testing data come from different radar platforms with different parameters,so cross-sensor experiments can provide evidence for the generalization.展开更多
针对探地雷达(Ground Penetrating Radar,GPR)与移动通信系统终端存在的频谱共用的电磁兼容性问题,着重分析了GPR接收中随机性射频干扰(Radio Frequency Interference,RFI)的性质,以及该类RFI与GPR目标回波信号在小波多尺度分解中分布...针对探地雷达(Ground Penetrating Radar,GPR)与移动通信系统终端存在的频谱共用的电磁兼容性问题,着重分析了GPR接收中随机性射频干扰(Radio Frequency Interference,RFI)的性质,以及该类RFI与GPR目标回波信号在小波多尺度分解中分布的差异性,并基于此分析,提出了基于小波变换域的GPR随机RFI抑制算法,利用两种实测实验数据进行验证,结果表明,该方法能较好地抑制GPR的随机性RFI。展开更多
当前,针对无线电引信的信息型干扰因效率较高、效果显著而受到广泛的关注。为保证无线电引信在战场上稳定发挥毁伤效能,抗信息型干扰技术成为无线电引信抗干扰领域的研究热点。以引信抗干扰需求作为引入,从单模态、多模态和认知技术3个...当前,针对无线电引信的信息型干扰因效率较高、效果显著而受到广泛的关注。为保证无线电引信在战场上稳定发挥毁伤效能,抗信息型干扰技术成为无线电引信抗干扰领域的研究热点。以引信抗干扰需求作为引入,从单模态、多模态和认知技术3个方面来阐述无线电引信抗信息型干扰的研究现状。现有的抗信息型干扰手段存在分辨率恶化、信号处理方法不适用等诸多问题,结合频控阵-多输入多输出(frequency diverse array-multiple-input multiple-output,FDA-MIMO)技术独特的“S”形弯曲阵列方向图,从测向欺骗、低截获点状波束形成和抗主瓣干扰3个方面对FDA-MIMO技术抗干扰方法进行综述,并对每一种方法进行评述。最后,对基于FDA-MIMO的无线电近炸引信抗信息型干扰技术进行了展望。展开更多
文摘随着无线电技术的发展,射频干扰(radio frequency interference,RFI)对射电天文观测的影响越来越大,尤其是周期性RFI对天文观测的影响越来越显著。本文围绕宽带、高时间分辨率频谱数据,采用阈值计算、噪声通道过滤、快速傅里叶变换、周期计算、通道合并、来源分析和模板库建立等步骤,提出一种面向宽带频谱序列的周期RFI统计方法。将该方法应用于新疆天文台南山观测站26 m射电望远镜(Nan Shan 26 m Radio Telescope,NSRT)脉冲星观测终端数据,有效地检测并提取出了频谱序列中的周期性RFI,可为进一步电磁干扰缓解提供数据支撑。
基金Supported by the National Natural Science Foundation of China(62001489)。
文摘Synthetic aperture radar(SAR)is a high-resolution two-dimensional imaging radar.However,during the imaging process,SAR is susceptible to intentional and unintentional interference,with radio frequency inter⁃ference(RFI)being the most common type,leading to a severe degradation in image quality.To address the above problem,numerous algorithms have been proposed.Although inpainting networks have achieved excellent results,their generalization is unclear.Whether they still work effectively in cross-sensor experiments needs fur⁃ther verification.Through the time-frequency analysis to interference signals,this work finds that interference holds domain invariant features between different sensors.Therefore,this work reconstructs the loss function and extracts the domain invariant features to improve its generalization.Ultimately,this work proposes a SAR RFI suppression method based on domain invariant features,and embeds the RFI suppression into SAR imaging pro⁃cess.Compared to traditional notch filtering methods,the proposed approach not only removes interference but also effectively preserves strong scattering targets.Compared to PISNet,our method can extract domain invariant features and hold better generalization ability,and even in the cross-sensor experiments,our method can still achieve excellent results.In cross-sensor experiments,training data and testing data come from different radar platforms with different parameters,so cross-sensor experiments can provide evidence for the generalization.
文摘针对探地雷达(Ground Penetrating Radar,GPR)与移动通信系统终端存在的频谱共用的电磁兼容性问题,着重分析了GPR接收中随机性射频干扰(Radio Frequency Interference,RFI)的性质,以及该类RFI与GPR目标回波信号在小波多尺度分解中分布的差异性,并基于此分析,提出了基于小波变换域的GPR随机RFI抑制算法,利用两种实测实验数据进行验证,结果表明,该方法能较好地抑制GPR的随机性RFI。
文摘当前,针对无线电引信的信息型干扰因效率较高、效果显著而受到广泛的关注。为保证无线电引信在战场上稳定发挥毁伤效能,抗信息型干扰技术成为无线电引信抗干扰领域的研究热点。以引信抗干扰需求作为引入,从单模态、多模态和认知技术3个方面来阐述无线电引信抗信息型干扰的研究现状。现有的抗信息型干扰手段存在分辨率恶化、信号处理方法不适用等诸多问题,结合频控阵-多输入多输出(frequency diverse array-multiple-input multiple-output,FDA-MIMO)技术独特的“S”形弯曲阵列方向图,从测向欺骗、低截获点状波束形成和抗主瓣干扰3个方面对FDA-MIMO技术抗干扰方法进行综述,并对每一种方法进行评述。最后,对基于FDA-MIMO的无线电近炸引信抗信息型干扰技术进行了展望。
