Characterizing urban light sources using imaging spectrometry

Remote mapping of night lights has been used for decades for mapping urbanization and the global distribution of human activity. Most of this has been accomplished using remote sensing data from the Defense Meteorological Satellite Program (DMSP). The coarse spatial and spectral resolution of DMSP, however, has precluded discrimination of lighting types or spectral characteristics. Recent demonstrations using photography from the International Space Station and airborne multispectral simulations demonstrate significant potential, but high-spectral-resolution field and laboratory measurements indicate that these methods do not take full advantage of the spectral information available. This research demonstrates the use of imaging spectrometer data to identify, characterize, and map urban lighting based on spectral emission lines unique to specific lighting types. ProSpecTIR imaging spectrometer data were analyzed to extract spectral features and these were compared to spectral library measurements on a pixel-by-pixel basis, resulting in a detailed spatial map showing different lighting types. The nature and distribution of lights can be used as a surrogate for measurement of urban development.