Finding and using a good dark site.

[mura_gadi (Steve)]

Hello,

I thought I would ask what software/apps/sites people are using to help with locating a good dark site. Also the weather apps/sites etc you use in regards to weather forecasts - cloud/humidity/wind etc - accurate forecasts.

If you can post what you use over any of these sites or can think of other handy links please reply.


Thanks
Steve

I use:
Dark Sky Map:
Suggested: https://www.lightpollutionmap.info/#...FFFTFFFFFFFFFF
Includes altitude from DEM
https://www.darkskymap.com/nightSkyBrightness

Australian contour maps:
https://www.ga.gov.au/scientific-top...maps#heading-1


Wind-Particle-Humidity with Height :
https://earth.nullschool.net/#curren...37.391,-31.340

Google Maps for roads/trip distances

Astronomy Tools
http://clearoutside.com/forecast/-35.22/149.02
(though this is fairly average indicator of conditions I find - nice for moon rise/set and astro dark times etc)


Ps. Have to love earth.nullschool

[JA]

Hi Steve,

for assessing a potential site try lightpollutionmap.info here...
https://www.lightpollutionmap.info/#...FFFTFFFFFFFFFF

Type in the location/suburb/country you want and select from what comes up, then zoom around the map even at street level to pin point an area of interest. If you use the World Atlas 2015 overlay (in the panel on the top right), when you click on a particular location the sky brightness (in µcd/m^2, or mcd/m^2) data are reported and SQM value is reported. If you use the VIIRS data you can get more current years, but it is reported in less intuitive sky radiance terms.

Best
JA

[mura_gadi (Steve)]

Thanks JA - have updated the link.


For Trivia:

TYVM for your link it click some old memory mine didn't with the altitude data.

From what I read the under lying dataset is MODIS for the altitude, which is based on 250m squares. These squares were referred to as DEM blocks when I was a GIS user, someone else more current can say if that's a 30sec DEM.

DEMS.
DEM squares get smaller as you move away from the equator. (More accurate as you move N/S, exceptions see last point)
DEM altitude is normally a mean average of a small amount of points. (Its not many data points 16/25 4x4/5x5 grid points sort of thing).
DEMs are prone to error near slopes/buffs/cliff/ravines etc where you can get a large variance in the 250m block.


*MODIS is legacy stuff, so I'd be pretty sure the number of read points in a given grid square would be limited due to the size of the data collection. Been a long time since 30secs DEMs were the end game.

To save the high school brain from being woken - mean average is the lowest and highest point removed and the average of the remainder(I think...).