SWIR sky-glow cloud correlation with NIR and visible clouds: anurban and rural comparison

摘要

Between the wavelengths of the visible and the Short Wave Infrared (SWIR), the glow of the sky from chemical radiance and absorption changes dramatically. Thus too, the structure and appearance of clouds change. By directly and simultaneously examining clouds in an urban and a rural setting, we investigate the correlation between the appearance of clouds present in the SWIR, NIR, and visible. The experimental setup consists of two sensors, one a NIR to SWIR sensitive InGaAs array, and the other a visible CCD, both co-located on an AZ-EL mount, and both co-boresighted so that different viewing angles of the sky are possible. The SWIR sensor is sensitive from 0.9 μm to 1.7 μm. The CCD sensor collects cloud images in the visible region. By making corrections for focal length and pixel size, the visible and SWIR data can be compared. After taking several nights of data in the urban environment of Albuquerque, NM, the entire system was then re-located to a rural location in southern New Mexico.