W波段机载视频合成孔径雷达系统

W-band airborne video synthetic aperture radar system

合成孔径雷达(SAR)能够全天时全天候工作,在对地遥感领域具有广泛和深入的应用。视频SAR将SAR成像获得的空间维度信息拓展到时-空维度,可以获取更加丰富的遥感信息。传统SAR频段较低,导致合成孔径时间长,数据计算量大,高帧频输出难度很大;而低频段太赫兹波对目标细节感知能力强,合成孔径短,特别适合于微弱目标的视频感知。本文设计了一种工作在W波段的视频SAR系统,采用收发分置连续波固态前端体制,输出峰值功率1 W,最大发射带宽可达1 GHz;采用极坐标格式算法(PFA)结合GPU架构实现高帧率低延时成像。仿真试验表明,系统成像分辨力可达0.15 m,成像帧率约5 Hz。

Synthetic Aperture Radar(SAR)works all day and all weather,and has a wide application in the field of earth remote sensing.Video SAR expands the spatial dimension information obtained by SAR imaging to the space-time dimension to obtain richer remote sensing information.The low frequency band of traditional SAR leads to long synthetic aperture time,large amount of data calculation,and great difficulty in high frame rate output.However,the low frequency terahertz wave has strong perception on target details and short synthetic aperture,which is especially suitable for video perception of weak targets.A video SAR system working in the W-band is designed,which adopts the solid-state front end system of bistatic continuous wave,with peak output power of 1 W and maximum transmission bandwidth of 1 GHz.The Polar Format Algorithm(PFA)along with Graphics Processing Unit(GPU)processing architecture is employed to realize high frame rate and low delay imaging.The simulation results show that the imaging resolution of the system can reach 0.15 m and the imaging frame rate is 5 Hz.