运动误差对太赫兹圆迹SAR成像质量影响分析

Imaging quality analysis of terahertz circular SAR affected by the motion error

太赫兹圆迹合成孔径雷达(SAR)结合了太赫兹波和圆迹SAR技术,比传统的直线SAR具有更高的成像分辨力,在雷达领域拥有广阔的应用前景。雷达实际运动中存在的运动误差将导致成像聚焦差、旁瓣升高和分辨力下降,是影响雷达成像质量的重要因素,在太赫兹圆迹SAR中,雷达的成像质量受运动误差的影响是各个方位向的运动误差共同作用的。为了分析运动补偿时所需达到的精确度,建立了太赫兹圆迹SAR的运动误差模型,定量分析了运动误差存在时目标的峰值下降系数,并根据峰值下降系数分析了运动误差对成像质量的影响,包括分辨力、峰值旁瓣比(PSLR)和积分旁瓣比(ISLR)的变化,同时通过仿真验证了分析的正确性。

The Terahertz circular Synthetic Aperture Radar(SAR)which combines the terahertz wave and the circular SAR can obtain the higher imaging resolution compared to the traditional linear SAR,and it has a broad application prospect in the radar field.An important factor which influences the imaging quality of radar is the motion error in the real movement which will cause the bad focusing effect,high side lobe and decline in resolution.In the imaging process of terahertz circular SAR,the imaging quality affected by the motion error is determined by the motion errors in different directions together.In order to analyze the accuracy of motion compensation,this paper makes the model of motion error in the terahertz circular SAR and the quantitative analysis of target’s peak descent coefficient of target when the motion error exists.The changes of imaging qualities in cluded resolution,Peak Sidelobe Ratio(PSLR)and Integrated Sidelobe Ratio(ISLR)are quantitativly analyzed by the descent coefficient.Besides,this paper makes some simulations to prove the correctness of analysis.The analysis shows important guiding significance for the imaging of terahertz circular SAR.