The world atlas of zenith artificial night sky brightness is modelled with VIIRS DNB data and calibrated with more than 35,000 observations.

Measuring the brightness of the night sky has become an increasingly important topic in recent years, as artificial lights and their scattering by the Earth's atmosphere continue spreading around the globe. Several instruments and techniques have been developed for this task. We give an overview of these, and discuss their strengths and limitations. The different quantities that can and should be derived when measuring the night sky brightness are discussed, as well as the procedures that have been and still need to be defined in this context. We conclude that in many situations, calibrated consumer digital cameras with fisheye lenses provide the best relation between ease-of-use and wealth of obtainable information on the night sky. While they do not obtain full spectral Quality Meter" continue to be a viable option for long-term studies of night sky brightness and for studies conducted from a moving platform. Accurate interpretation of such data requires some understanding of the colour composition of the sky light. We recommend supplementing long-term time series derived with such devices with periodic all-sky sampling by a calibrated camera system and calibrated luxmeters or luminance meters.

We describe a system for rapidly measuring the brightness of the night sky using a mosaic of CCD images obtained with a low-cost automated system. The portable system produces millions of independent photometric measurements covering the entire sky, enabling the detailed characterization of natural sky conditions and light domes produced by cities. The measurements are calibrated using images of standard stars contained within the raw data, producing results closely tracking the Johnson V astronomical standard. The National Park Service has collected hundreds of data sets at numerous parks since 2001 and is using these data for the protection and monitoring of the night-sky visual resource. This system also allows comprehensive characterization of sky conditions at astronomical observatories. We explore photometric issues raised by the broadband measurement of the complex and variable night-sky spectrum, and potential indices of night-sky quality. J J mass vs. for the SBIG camera. The line of slope Ϫ0.048 mag per V Ϫ v J magnitude of represents the color transformation term between stellar (B Ϫ V ) J J photometry with this camera and photometry in the Johnson V band as published in the Hipparcos catalog. Instrumental Zero Point and Color TermsInstrumental zero points and color terms were set for each camera by determining the relation between , air mass, V Ϫ v J and standard color for standard-star measurements (B Ϫ V ) J J ( and as published in the Hipparcos catalog). A V [B Ϫ V ] J J J

No abstract

No abstract