American economists Vernon Henderson and David Weil recently analysed over a decade's worth of global night-light data from DMSP. Their research shows a link between changes in a country's Gross Domestic Product (GDP) and the intensity of its electric lighting, both domestic and commercial: on average, as a country's GDP increases, its night-time light emission becomes more intense.
Chris Elvidge leads a team that removes contaminating natural phenomena like moonlight, lightning, and forest fires from the images, but he says that human choices of how buildings and streets are lit, and even which variety of light bulbs are used, all alter the patterns and intensity of light, adding uncertainty to any conclusions.
Sutton is suggesting to NASA that it should develop and launch a Nightsat, a state-of-the-art satellite devoted solely to gathering high resolution, full-colour data on nocturnal lights across the globe.
Questions
1. Improved data on night-time light levels could have wide-ranging applications in future.
2. The use of different types of lighting may affect the reliability of satellite data.
3. Levels of man-made night-time illumination reflect national prosperity.