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直视合成孔径激光成像雷达采用内发射场直接波面变换平动扫描发射,通过自差接收实现高分辨率成像。由于远场目标位置的光场分布取决于内发射光场,因此内发射场的波前像差会对激光雷达图像质量产生影响。采用Zernike多项式描述波前像差,对初级像差造成直视合成孔径激光成像雷达的成像影响进行了研究,理论分析和仿真结果表明:离焦、象散、彗差和球差对成像的影响最为严重,像差越大,其对成像分辨率的影响也越大。当像差的均方根值小于0.05λ时,对成像分辨率的影响很小,当像差的均方根值为0.25λ时,其象散和彗差引起成像分辨率近似增大到原来的3倍。彗差和球差还造成不同目标位置的成像分辨率不同,离中心位置越远,成像分辨率增加越快。
The direct-view synthetic aperture laser imaging radar uses the internal emission field direct wavefront transform and translational scanning to transmit, and achieves high-resolution imaging by self-difference reception. Since the distribution of the light field at the far field target location depends on the internal emission light field, the wavefront aberration of the internal emission field affects the image quality of the lidar. The Zernike polynomial is used to describe the wavefront aberration, and the effect of primary aberration on the imaging of laser synthetic aperture laser imaging radar is studied. The theoretical analysis and simulation results show that the effects of defocus, astigmatism, coma and spherical aberration on imaging The most serious, the greater the aberration, the greater its impact on imaging resolution. When the RMS value of aberration is less than 0.05λ, the effect on imaging resolution is small. When the RMS value of aberration is 0.25λ, the resolution of imaging caused by astigmatism and coma enlarge approximately 3 times. Coma and spherical aberration also result in different imaging resolutions at different target positions, and the farther away from the center, the faster the imaging resolution increases.