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Nightscape Survey System
The 2001 National Park Service (NPS) designation of pristine “nightscapes” as a natural resource led to a program to document the quality and establish baseline management conditions at national parks across our nation. As no suitable technology existed to accomplish this, NPS scientists developed their own. In 2010 AIM concluded its cooperative agreement with the NPS with a sucessful demonstration of AIM's independently owned and operated Nightscape Survey System.
This system is capable of accurately documenting levels of artificial light present across the full dome of the sky. Traditional mapping reduces sky quality to a single number that can be plotted on terrestrial maps. AIM's Nightscape Survey System represents the full "spatial diversity" of its data as fish-eye (right) and panoramic projections (below).
This method makes it possible to document the precise amount of Astronomical Sky Glow coming from every part of the sky. It accurately documents not only the overall nightscape quality, but also the major artificial sources, known as "light domes." Most significantly, the Nightscape Survey System does so in units of visible light carefully calibrated to the human - the Astronomical V (visual) Band.
The phase one system’s hardware consisted of a robotic camera that scans the sky, taking 104 images over 30 minutes. Custom software that searches each image for stars of well-understood brightness. The system automatically identified such stars and precisely calibrated the brightness of each image. The software then removed all stars from the image, leaving only the glow remaining between the stars—the artificial light.
The result was the world’s most precise measurement of how much artificial light is present in every quadrant of the sky. The results are visually stunning—or alarming, as the case may be—and very accessible to the non-scientist whose understanding of this newly-recognized natural resource is vital to its protection.
