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New tool to find where light pollution come from

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#1 Apollo20


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Posted 20 April 2021 - 11:41 AM

Dear all,
I’d like to share with you a new tool to find the major contributors to the light pollution of a site of your choice.
Based on the works of Salvador Bará, Raul Lima and me (see: https://lightingjour...article/view/87 and https://royalsociety...098/rsos.201501 ), Jurij Stare implemented in his website (https://www.lightpollutionmap.info/#zoom=4.00&lat=45.8720&lon=14.5470&layers=B0FFFFFFTFFFFFFFFF) a tool that allows you to select a site (e.g. your preferred site of observation) and then select an area (e.g. the nearest village or a big city far away) and calculate the contribution of the light sources present in that area to the zenith brightness at your site.
Then you can select a reduction or an increase of the light coming from the selected area, to evaluate the consequent change in quality of your sky at zenith. You can also do the reverse, imposing a sky brightness level to be reached and see how much reduction (or increase) is needed to get there. Say, that at the site the sky brightness given by the New World Atlas (https://advances.sci...nt/2/6/e1600377 ) is 21.3 and you want to reach 21.4, the tool will say what reduction is needed in the selected area. If even a total reduction will not give the desired reduction, then a different and/or larger area needs to be selected.

<post edited by moderator>
Once opened, the lightpollutionmap website shows you the New World Atlas layer, but the tool will automatically change the layer to VIIRS 2020, the newest layer with light sources (you can select a previous year, if needed). You find it in the upper left corner: click on ‘Toggle extended toolbar’, then on ‘Zenith brightness simulations’) and start working!


Fabio Falchi

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#2 Tony Flanders

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Posted 21 April 2021 - 05:19 AM

This is a brilliant idea. At sites in the U.S. Northeast, with major cities at various distances and minor ones as well, I have always wondered what fraction of the skyglow comes from each city. For instance, how much does Albany, NY, contribute to the light pollution at Stellafane, VT? Thanks for all your hard work and ground-breaking contributions, Fabio Falchi!

Edited by Tony Flanders, 21 April 2021 - 05:21 AM.

#3 eddyca


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Posted 22 April 2021 - 07:23 PM

Ohhh!! Thank you so much.

#4 alphatripleplus


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Posted 23 April 2021 - 03:23 PM

A very interesting tool, indeed. Thanks.

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