2020年 第49卷 第5期
光谱成像技术是深空探测领域的重要技术手段,可服务于多种空间科学实验。针对深空探测领域对光谱载荷的高稳定性、高光利用率的需求,提出一种新型深空高光谱衍射计算成像探测技术,将衍射光谱成像技术和光场成像技术结合,解决衍射光谱推扫成像系统中探测器需要大范围扫描问题,实现一次拍照获取目标空间信息和光谱信息,即快照式成像。这对未来深空探测高光谱成像仪的设计和研究具有指导意义。
A novel ultra- low-power readout integrated circuit (ROIC) for 1 024×1 024 ultraviolet (UV) AlGaN focal plane arrays (FPA) with 18 μm-pitch was presented. In order to optimize power consumption for UVFPA readout circuit these methods were adopted, which including single-terminal amplifier under subthreshold region as CTIA amplifier, common current source load for source follow (SF) buffer in column pixels and level shift circuits, and time-sharing tail current source for column buffer. The smallest operational current of CTIA in pixel unit is only 8.5 nA with 3.3 V power supply by using single-terminal amplifier. The ROIC has been fabricated in SMIC 0.18 μm 1P6M mixed signal process and also achieved better performances with the novel design of bias current adjustable. Furthermore, the overall power consumption of the chip is 67.3 mW at 2 MHz in 8-outputs mode by the above methods according to the experimental results.
Infrared radiometry technology is an important means to characterize the infrared signature of targets, and atmospheric correction is a requisite step to obtain the real radiance of targets. A nonlinear atmospheric correction (NLAC) method was proposed to improve the infrared radiometric accuracy for long distance targets in this paper. This method used near-range standard reference source measurement (NRSRM) to calculate the actual atmospheric transmittance and path radiation simultaneously at different locations in a real-time environment. And the theoretical atmospheric transmission and path radiation under the corresponding conditions could be obtained from the atmospheric radiation transmission software as well. Neural network technology was applied to fit the non-linear relationship between them. Thus, the atmospheric transmittance and path radiation over long distances could be predicted to achieve atmospheric correction. Simpler linear atmospheric correction (LAC) and linear enhancement atmospheric correction (LEAC) were also carried out for comparison. The experimental results indicate that the infrared radiometric average error of the proposed method is 6.45%, which is much lower than that of the conventional method, LAC and LEAC that are 16.17%, 11.27% and 7.44%, respectively.