Target micromotion not only plays an important role in target recognition but also leads to esoteric characteristics in synthetic aperture radar （SAR） imaging. This paper finds out an interesting phenomenon, i.e. th...Target micromotion not only plays an important role in target recognition but also leads to esoteric characteristics in synthetic aperture radar （SAR） imaging. This paper finds out an interesting phenomenon, i.e. the angular extent effect, in micro-motion target images formulated by the polar format algorithm. A micromotion target takes on multiple pairs of paired echoes （PEs） around the true point, and each PE extends for an angle which is exactly equal to the angular extent of the synthetic aperture, regardless of the micromotion frequency. The effect is derived and interpreted by using the characteristics of Bessel functions. Then it is demonstrated by simulation experiments of a target with different micromotion frequencies. The revelation and interpretation of the effect is highly beneficial to micromotion-target SAR image understanding as wel as target recognition.展开更多
作为一种全新的雷达运动目标识别方法,微多普勒效应能够显示出目标自身更为丰富的运动学信息,同时也会造成动目标SAR成像模糊等传统理论无法克服不利影响。通过研究振动和转动SAR目标回波模型,综合出SAR微动目标统一的距离方程及SAR回...作为一种全新的雷达运动目标识别方法,微多普勒效应能够显示出目标自身更为丰富的运动学信息,同时也会造成动目标SAR成像模糊等传统理论无法克服不利影响。通过研究振动和转动SAR目标回波模型,综合出SAR微动目标统一的距离方程及SAR回波表达式,推导出回波方位向将呈现正弦调频(sinusoidal frequency modulation,SFM)信号等周期性特点。最后,通过计算机仿真验证了本文结果的正确性。展开更多
该文首先建立了旋转目标的时频模型、多普勒模型;然后利用旋转目标的多普勒特点分析其SAR成像特点;最后分析了三孔径InSAR中偏置相位中心天线(DPCA:Displaced Phase Centre Antenna)杂波对消以及沿迹干涉(ATI:Along-Track Interferomet...该文首先建立了旋转目标的时频模型、多普勒模型;然后利用旋转目标的多普勒特点分析其SAR成像特点;最后分析了三孔径InSAR中偏置相位中心天线(DPCA:Displaced Phase Centre Antenna)杂波对消以及沿迹干涉(ATI:Along-Track Interferometry)的物理意义,得到了三孔径干涉对消处理后旋转目标的幅度、相位特性。这种分析方法比以往斜距近似分析更简单直观,并且仿真实验验证了结论的正确性,并且分析了其相位缠绕可能造成的动目标检测误差。为研究微运动目标在多通道SAR中的成像特性研究提供了初步的参考,证明了微动类型干扰对SAR动目标检测也能够形成不利影响。展开更多
基金supported by the National Natural Science Foundationof China(6130214861101182)
文摘Target micromotion not only plays an important role in target recognition but also leads to esoteric characteristics in synthetic aperture radar （SAR） imaging. This paper finds out an interesting phenomenon, i.e. the angular extent effect, in micro-motion target images formulated by the polar format algorithm. A micromotion target takes on multiple pairs of paired echoes （PEs） around the true point, and each PE extends for an angle which is exactly equal to the angular extent of the synthetic aperture, regardless of the micromotion frequency. The effect is derived and interpreted by using the characteristics of Bessel functions. Then it is demonstrated by simulation experiments of a target with different micromotion frequencies. The revelation and interpretation of the effect is highly beneficial to micromotion-target SAR image understanding as wel as target recognition.
文摘作为一种全新的雷达运动目标识别方法,微多普勒效应能够显示出目标自身更为丰富的运动学信息,同时也会造成动目标SAR成像模糊等传统理论无法克服不利影响。通过研究振动和转动SAR目标回波模型,综合出SAR微动目标统一的距离方程及SAR回波表达式,推导出回波方位向将呈现正弦调频(sinusoidal frequency modulation,SFM)信号等周期性特点。最后,通过计算机仿真验证了本文结果的正确性。
文摘该文首先建立了旋转目标的时频模型、多普勒模型;然后利用旋转目标的多普勒特点分析其SAR成像特点;最后分析了三孔径InSAR中偏置相位中心天线(DPCA:Displaced Phase Centre Antenna)杂波对消以及沿迹干涉(ATI:Along-Track Interferometry)的物理意义,得到了三孔径干涉对消处理后旋转目标的幅度、相位特性。这种分析方法比以往斜距近似分析更简单直观,并且仿真实验验证了结论的正确性,并且分析了其相位缠绕可能造成的动目标检测误差。为研究微运动目标在多通道SAR中的成像特性研究提供了初步的参考,证明了微动类型干扰对SAR动目标检测也能够形成不利影响。
