摘要: |
提出了采用步进频率结合平面扫描的THz雷达近场成像系统设计方案,基于宽带全息成像原理,可以实现三维高分辨率近场成像。采用多通道收发探头阵列缩短机械扫描行程,提高成像速度。给出了基于快速傅里叶变换(Fast Fourier Transform,FFT)和Stolt插值的三维图像重建算法,成像理论分辨率与波长相当。利用THz矢量网络分析仪和辅助设备,搭建了0.215~0.33 THz成像试验装置,完成了对多层金属-泡沫目标三维成像,成像分辨率达到预期水平,验证了系统设计和三维图像重建算法的正确性。 |
关键词: THz雷达 宽带全息成像 三维重建算法 步进频率 |
DOI: |
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Design and imaging test of a 0.33 THz radar 3D near-field imaging system |
HUANG Jian,PEI Naichang,WANG Zhihui,SUN Zhimin |
(Southwest China Institute of Electronic Technology,Chengdu 610036,China;Chengdu Spaceon T&C Technology Co.,Ltd.,Chengdu 610036,China) |
Abstract: |
A scheme of THz radar system for near-field imaging is presented.The radar system,with frequency-stepping signal waveform and scanned in a plan,can realize 3D imaging with high resolution based on wide-band holographic imaging principle.Total scanning path can be shorten by using a sensor array with multi-channel.Thus the image frame rate can be improved.The 3D image reconstruction algorithm based on fast Fourier transform(FFT) and stolt interplation is given.The theoretical image resolution near wavelength is achieved.A 0.215~0.33 THz experimental imaging set is built up using THz vector network analyzer and other devices.3D imaging of a target composed of several layers of metal,foam and absorbing material is acquired through the set with resolution as expected,which proves the validity of system design as well as 3D reconstruction algorithm. |
Key words: THz radar wide-band holographic imaging 3D image reconstruction algorithm frequency-stepping scan |