<p>At <a href="https://www.lightpollutionmap.info/#zoom=6.86&amp;lat=34.1895&amp;lon=-114.9452&amp;layers=B0FFFFFFTFFFFFFFFFF" rel="nofollow noreferrer">this light pollution map</a> they show degrees of light pollution but they have 3 numbers to quantify light pollution and they do not explain in the help section what the numbers mean:</p>
<p>The numbers are <a href="https://en.wikipedia.org/wiki/Sky_quality_meter" rel="nofollow noreferrer">SQM</a>, brightness and artificial brightness.  I get that for the last two the lower the better for viewing stars, but I can't figure out if brightness perhaps includes artificial brightness.</p>
<p><a href="https://i.sstatic.net/pyN4f.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/pyN4f.png" alt="Screen shot of the legend" /></a></p>

CC BY-SA 4.0
2021-01-22T08:31:20.443Z
I added the screenshot which shows what I guess what you are talking about. Feel free to replace it, if you are talking about something else.
B--rian
CC BY-SA 4.0
2021-01-22T08:33:27.173Z
@JamesK Since you commented on [my question about light pollution](https://astronomy.stackexchange.com/questions/40632/how-many-streetlights-should-we-turn-off-to-decrease-light-on-the-ground-by-abou) I guess you might be able to help bobsmith76
B--rian
CC BY-SA 4.0
2021-01-22T09:32:05.987Z
Does https://astronomy.stackexchange.com/questions/21484/in-an-area-with-lots-of-light-pollution-which-clear-sky-clock-parameter-is-most help you?
B--rian
CC BY-SA 4.0
2021-01-22T10:14:06.970Z
No, I saw the website cleardarksky.com and it's too confusing.
bobsmith76
<light-pollution>
Light Pollution: what is the difference between artificial brightness and brightness and SQM
bobsmith76
# Light Pollution: what is the difference between artificial brightness and brightness and SQM

(Asked by: username_0 on 2021-01-21)

At [this light pollution map](https://www.lightpollutionmap.info/#zoom=6.86&lat=34.1895&lon=-114.9452&layers=B0FFFFFFTFFFFFFFFFF) they show degrees of light pollution but they have 3 numbers to quantify light pollution and they do not explain in the help section what the numbers mean:

The numbers are [SQM](https://en.wikipedia.org/wiki/Sky_quality_meter), brightness and artificial brightness. I get that for the last two the lower the better for viewing stars, but I can't figure out if brightness perhaps includes artificial brightness.

[![Screen shot of the legend](https://i.sstatic.net/pyN4f.png)](https://i.sstatic.net/pyN4f.png)

**Tags:** light-pollution

> **Comments:**
> **username_1**: I added the screenshot which shows what I guess what you are talking about. Feel free to replace it, if you are talking about something else.  
> **username_1**: @JamesK Since you commented on [my question about light pollution](https://astronomy.stackexchange.com/questions/40632/how-many-streetlights-should-we-turn-off-to-decrease-light-on-the-ground-by-abou) I guess you might be able to help username_0  
> **username_1**: Does https://astronomy.stackexchange.com/questions/21484/in-an-area-with-lots-of-light-pollution-which-clear-sky-clock-parameter-is-most help you?  
> **username_0**: No, I saw the website cleardarksky.com and it's too confusing.  

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## 0 answers

