Twilight and the Naked-Eye Observer: Models and High- Resolution Measurements

暮光之城和肉眼观察者：模型和高分辨率测量

• 批准号: 9414290
• 负责人: Alistair Fraser
• 金额: $ 24.53万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-07-01 至 1998-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9414290&HistoricalAwards=false
• 关键词: Twilight; Naked; Eye; Observer; Models

Fraser/Abstract This proposal requests research support for optical remote sensing of twilight. Like many other researchers, we are interested in using twilight's optical structure to evaluate the verisimilitude of atmospheric scattering models. However, unlike others, we propose to do our testing with a remote sensing system that combines: a) multiple spectral channels with broad bandwidths, and b) very high spatial and temporal resolutions. This remote sensing system is human trichromatic color vision, which has the obvious disadvantage that it is essentially subjective. However, trichromatic analogues of color vision, such as color film and digital imaging systems, let us map their objective and reproducible responses into those of a typical naked- eye observer. Other advantages gained by using photography and digital imaging include the ability to easily analyze: a) spectra from large portions (or all) of the twilight at once, b) the temporal evolution of twilight spectra at very high resolutions, and c) the spatial details of twilight polarization. Specifically, we plan to use digital image analysis of color slides, occasionally corroborated by spectroradiometry, to explore the photometric, polarimetric, and colorimetric structure of twilight. With a variety of data inversion techniques, we will then assess how well various atmospheric scattering models account for twilight as seen by the naked-eye observer (we include here observers equipped with simple linear polarizers). In the past, twilight's ephemeral nature has restricted researchers to gathering only limited amounts of photometric and polarimetric data, and then usually only as a means of constructing atmospheric soundings. Colorimetric studies of twilight are even rarer. As worthwhile as twilight-derived atmospheric soundings are, here we propose a quite different goal: measuring and modeling twilight's largely unquantified visual structure.

弗雷泽/摘要 这项建议要求对曙暮光的光学遥感提供研究支持。 像许多其他研究人员一样，我们有兴趣使用曙暮光的光学结构来评估大气散射模型的真实性。 然而，与其他人不同的是，我们建议用一个遥感系统进行测试，该系统结合了：a）具有宽带的多光谱通道，以及B）非常高的空间和时间分辨率。 这种遥感系统是人类的三色视觉，它有一个明显的缺点，它本质上是主观的。 然而，彩色视觉的三色模拟物，如彩色胶片和数字成像系统，让我们将它们的客观和可再现的反应映射到典型的裸眼观察者的反应中。 通过使用摄影和数字成像获得的其他优点包括能够容易地分析：a）一次来自大部分（或全部）暮光的光谱，B）在非常高的分辨率下暮光光谱的时间演变，以及c）暮光偏振的空间细节。 具体来说，我们计划使用彩色幻灯片的数字图像分析，偶尔由分光辐射测定法证实，探索暮光的光度，偏振和色度结构。 通过各种数据反演技术，我们将评估各种大气散射模型如何解释裸眼观察者（我们在这里包括配备简单线性偏振器的观察者）所看到的暮光。 在过去，暮光的短暂性限制了研究人员只能收集有限数量的光度和偏振数据，而且通常只能作为构建大气探测的一种手段。 对暮光的色度学研究更是少之又少。 尽管黄昏的大气探测是有价值的，但在这里我们提出了一个完全不同的目标：测量和建模黄昏的基本上未量化的视觉结构。