摘要
介绍了曲线合成孔径雷达(CLSAR)的基本概念,推导了CLSAR的chirp信号回波数据模型,并在此基础上对CLSAR的三维目标重建机理进行了详细的分析。指出由于旁瓣的影响,传统的基于FFT的反演成像方法在曲线孔径下不再有效,进而采用基于谱估计的RELAX算法实现三维目标的特征提取。最后,通过系统仿真,验证了CLSAR利用RELAX算法实现三维目标特征提取的有效性和优越性。
In this paper, the concept of Curvilinear Synthetic Aperture Radar (CLSAR) is introduced and the returned chirp signal data model for CLSAR is described. Based on this model, the principle of three dimensional target reconstruction of CLSAR is analyzed detailedly. The 2D FFT analysis is conducted in the Cross range-Elevation plane of the curvilinear apertures, and the results show that the traditional FFT-based SAR imaging method is no longer practical in the curvilinear apertures situation because of the effect of large side lobe. As the substitution of the FFT-based imaging method, the 3D target feature extraction method using RELAX algorithm based on spectrum estimation is introduced to solve the sidelobe problem. It has already been proved that the RELAX algorithm can be used efficiently to estimate the dominant scatters' discrete spectrum parameters from the noise and clutter's continuous spectrum if the targets can be divided into several dominant scatters. Furthermore, the computer simulation of the ideal full aperture and several specific curvilinear apertures are conducted. The simulation results show the validities and advantages of the RELAX-based 3D target feature extraction method for CLSAR. And the results also show that the parabolic aperture is the relative optimal choice among the curvilinear apertures we used in the simulation.
出处
《遥感技术与应用》
CSCD
2004年第6期493-497,共5页
Remote Sensing Technology and Application
