摘要
为满足海洋水色遥感器大动态范围监测的需求,以推扫式成像光谱仪为例,提出一种基于多挡增益的自适应成像方法。从遥感器动态范围与信噪比的矛盾分析出发,阐述了逐像元自适应读取方法的优势,给出相应的系统设计。由海洋成像场景确定满阱电荷限制,并利用系统信噪比及动态范围约束,仿真分析得出最优挡位个数及比例。结果表明,当增益挡位为4挡,满阱电荷分别为2.5 Me-(超低增益)、500 ke-(低增益)、100 ke-(中等增益)、20 ke-(高增益)时,成像效果最佳。基于此设置,光谱成像系统总动态范围可达116 dB,典型入射辐亮度下各通道平均信噪比为767.37。同时,利用中等分辨率大气辐射传输模型(MODTRAN)对该成像方法进行了验证,除云层的第10通道出现饱和外,其余均满足动态范围和信噪比要求。
In this study,an adaptive multiple-gain imaging method was proposed based on a pushbroom imaging spectrometer to meet the demands of high dynamic range(DR)monitoring using an ocean color remote sensor.Further,the advantage of the pixel-by-pixel adaptive readout method was explained by analyzing the differences in case of DR and the signal-to-noise ratio(SNR),and the corresponding system design was presented.The limit of full well charge was determined based on the ocean imaging scene,and the optimal number and proportion of gains were obtained via system simulation based on the constraints associated with respect to SNR and DR.The results denote that the optimal imaging effect can be obtained when the number of gains is four and the full well charges are 2.5 Me-(ultra-low gain),500 ke-(low gain),100 ke-(medium gain),and 20 ke-(high gain).Based on this setting,the total DR of the spectral imaging system can become 116 dB;the average SNR of each channel under typical radiance becomes 767.37.Furthermore,the medium-resolution atmospheric radiation transfer model was used to verify this imaging mode.The conditions with respect to the channels meet the requirements of DR and SNR,except for the 10th channel of the cloud that appears to be out of saturation.
作者
金鹏飞
汤瑜瑜
危峻
Pengfei Jin;Yuyu Tang;Jun Wei(Key Laboratory of Infrared Detection and Imaging Technology of the Chinese Academy of Sciences,Shanghai 200083,China;Shanghai Institute of Technical Physics of the Chinese Academy of Sciences,Shanghai 200083,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《光学学报》
EI
CAS
CSCD
北大核心
2020年第11期84-90,共7页
Acta Optica Sinica
基金
国家自然科学基金(11573049)。
关键词
成像系统
海洋遥感
光谱成像
动态范围
自适应
多挡增益
imaging system
ocean remote sensing
spectral imaging
dynamic range
adaption
multiple-gain
