基于成像时刻校准的混合域TDICMOS成像技术研究

Research on hybrid domain TDICMOS imaging technology based on imaging time calibration

随着航天遥感领域超高分辨率成像电子学中行频的不断提升,一个积分时间内光生电荷数量逐渐减少,弱光成像能力有所下降,电子学中需要采用增大时间延迟积分级数的方法弥补能量的不足。传统数字域累加探测器有着引入过多噪声与帧频受限的多项弊端,而电荷域探测器的超大级数累加会带来电荷转移效率的下降和图像的混叠。基于此,文章在采用低功耗、高集成度TDICMOS基础上,提出了一种基于电荷域和数字域混合的新型累加方式,并对影响弱光成像像质水平的主要指标进行分析。随后针对混合域累加方式下多感光单元间的像质退化,提出一种基于图像配准的成像时刻校准方法,通过多片感光单元间隔测量和成像时刻时序微调有效改善了大积分级数电荷运动与景物运动的失配程度。最后通过滚筒测试验证了成像时刻校准方法的有效性,通过性能测试验证了混合域成像在弱光照下探测能力的提升。结果表明,文中所提方法有效地解决了TDI型探测器的主要瓶颈,为超高分辨率遥感相机提供了有效的解决方案。

With the increase of line frequency of high resolution imaging electronics in the field of high resolution space remote sensing,the number of photo-electrons in one integration time is gradually reduced,and the imaging ability of the camera in weak light decreases.In electronics,it is necessary to increase TDI stages to make up for the lack of energy.The traditional digital domain accumulation sensor has many disadvantages,such as excessive noise and low frame rate.The large TDI sensor in charge domain will reduce the charge transfer efficiency and increase image aliasing.Based on TDICMOS imaging with low power consumption and high integration,a new hybrid accumulation method based on charge domain and digital domain was proposed.The main indexes that affect the image quality of weak light imaging were analyzed.Then,aiming at the degradation of image quality between multiple photosensitive units under the mode of hybrid domain accumulation,an imaging time calibration method based on image registration was proposed.Through the interval measurement of multiple photosensitive units and the fine-tuning of imaging signal timing,the mismatch between the large integral series charge motion and the scene motion was effectively improved.Finally,through the roller target test,the effectiveness of the imaging time calibration method was verified.The imaging ability of hybrid domain imaging in weak light was also verified by performance test.The results show that the proposed method in this paper can effectively solve the main bottleneck problem of TDI sensor,provides an effective solution for high resolution remote sensing camera.