Night Sky Maps and Graphics

The data mosaic sets in the following gallery contain two figures: the first, full resolution mosaic, factors "all sky" brightness; the second shows estimated artificial sky glow.

The full resolution mosaic is rendered in false color. Individual images are placed in the mosaic after correction for pointing errors, and projected into a Hammer-Aitoff equal area projection with the horizon at the center vertically and a fixed azimuth at the center horizontally. The false color scheme reveals a wide dynamic range of sky brightness values in a logarithmic scale from 14 to 23 mag arcsec-2. The all-sky image mosaic (zenith to 6 degrees below the level horizon) contains about 34 million pixels. Land features and individual light trespass sources are often visible in this rendering.

The estimated artificial sky glow mosaic is the sky brightness mosaic subjected to pixel by pixel subtraction of a registered natural sky model mosaic (the natural sky model is not shown as a graphic in the report) rendered in the same false color scale as the full resolution mosaic. The resolution is 0.05 degrees per pixel. Land features and individual light trespass sources are masked out so that only sky luminance from artificial sky glow is shown. This is an at-a-glance representation of the amount of light pollution from sky glow observed at the site. Artificial sky glow will always be brighter near the horizon than at the zenith and its impact on the natural lightscape substantial.

Last updated: September 14, 2016

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