RUI: Spectral Imaging of Overcast Skies

RUI：阴天的光谱成像

• 批准号: 0540896
• 负责人: Raymond Lee
• 金额: $ 18.2万
• 依托单位: United States Naval Academy
• 依托单位国家: 美国
• 项目类别: Interagency Agreement
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-02-01 至 2009-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0540896&HistoricalAwards=false
• 关键词: RUI; Spectral; Imaging; Overcast; Skies

The scientific objective of this research is to use newly available spectral imaging techniques to quantify and thus better understand overcasts' visible features. Such improvements will create new observational criteria for testing the realism of atmospheric radiative transfer models of overcasts' visible-wavelength spectral structure.The intellectual merit of the proposed research is that it would investigate overcasts in a fundamentally new way by complementing conventional spectroradiometry with high-resolution spectra extracted from digital images. This combination permits new kinds of analyses of overcasts' often rapidly changing features. Before now, studying the fine angular details of overcast radiance spectra has not been possible (and certainly not second-by-second), so the proposed research constitutes a wholly new method of atmospheric passive remote sensing. No comparable work exists for narrow field-of-view overcast radiances. The spectral structure of overcast radiances is useful in describing the spatial distribution of cloud optical depth and absorptivity. This in turn offers insights into details of the near-surface heat budget.With suitable data inversion techniques, various atmospheric scattering models will be tested to see how well they account for a given overcast's visible structure, including details seen through linear polarizers. Currently, no detailed observational study of overcast polarization seems to exist. Such wide-ranging observations can provide valuable new insights into everyday phenomena that are now thought to be well understood both theoretically and phenomenologically.The broader impacts of the study will be derived from benefits to science education and impacts on the general public. The digital imaging techniques developed for NSF-sponsored research will be translated into both daily classroom instruction and yearlong honors research projects for Naval Academy midshipmen. An improved understanding of the spatial and spectral distribution of overcast radiances has practical applications in many areas ranging from interior lighting and highway safety to plant growth and development. The principal investigator's presentations are apt to be a powerful recruiting tool for future atmospheric scientists and also for outreach to the general public.

这项研究的科学目标是使用新的光谱成像技术来量化，从而更好地了解覆云的可见特征。这些改进将为检验阴天可见光波长光谱结构的大气辐射传输模型的真实性创造新的观测标准，拟议研究的智力价值在于，它将通过从数字图像中提取的高分辨率光谱补充传统的分光辐射度法，以一种全新的方式研究阴天。这种结合允许对阴天经常快速变化的特征进行新的分析。在此之前，研究阴天辐射光谱的精细角度细节是不可能的（当然也不是逐秒的），因此所提出的研究构成了一种全新的大气被动遥感方法。对于窄视场的阴天辐射，没有类似的工作。云辐射的光谱结构对描述云光学厚度和云吸收率的空间分布是有用的。通过合适的数据反演技术，将对各种大气散射模型进行测试，以了解它们在多大程度上解释了给定阴天的可见结构，包括通过线性偏振器看到的细节。目前，似乎还没有详细的观测研究的阴天偏振。这种广泛的观察可以为日常现象提供有价值的新见解，这些现象现在被认为在理论和现象学上都得到了很好的理解。这项研究的更广泛影响将来自科学教育的好处和对公众的影响。为NSF赞助的研究开发的数字成像技术将被转化为日常课堂教学和为期一年的海军学院海军学员荣誉研究项目。更好地了解阴天辐射的空间和光谱分布在许多领域有实际应用，从室内照明和公路安全到植物生长和发育。首席研究员的演讲很可能成为未来大气科学家的一个强有力的招募工具，也是向公众宣传的一个工具。