Orpington Astronomical Society

Astronomy => Technical => Topic started by: The Thing on Mar 26, 2023, 14:34:41

Title: SQM Measurement without a fancy meter
Post by: The Thing on Mar 26, 2023, 14:34:41
Hi All,

Just been playing with software and found ASTAP can measure your SQM value from an image. I fed it a single raw sub (important: not stretched or debayered in ASTAP), raw dark and raw flat (all FITS images in my case), solved the image then used the new(ish) [Tools], [SQM report based on an image] function. Mine worked out as 21.85  8)  but then the French have turned of the streetlights and I'm pretty much in the countryside.

Hope that's useful, it means if you have been anywhere e.g. Cairds Farm and you have some subs you can see what the sky was like that night. Now to dig out some old Deep Sky Camp data!

Duncan
Title: Re: SQM Measurement without a fancy meter
Post by: Carole on Mar 27, 2023, 11:29:49
I have an App on my phone which will measure SQM.  As I recall it was a free download.

You certainly have lovely dark skies.

Carole   
Title: Re: SQM Measurement without a fancy meter
Post by: The Thing on Mar 27, 2023, 13:17:33
An app on your phone? How is it calibrated? All the ones I've ever seen require an external sensor as phone light sensors and cameras aren't up to it. Of course the latest ones might be.
Title: Re: SQM Measurement without a fancy meter
Post by: JohnH on Mar 27, 2023, 13:25:18
No idea how accurate it is but I have an app on my iPhone called "Dark Sky Meter" it gave a reading of 19.12 here near Bromley South Station.
Title: Re: SQM Measurement without a fancy meter
Post by: The Thing on Mar 27, 2023, 18:24:37
Quote from: JohnH on Mar 27, 2023, 13:25:18No idea how accurate it is but I have an app on my iPhone called "Dark Sky Meter" it gave a reading of 19.12 here near Bromley South Station.


Was that under the High Street road bridge? :lol:
Title: Re: SQM Measurement without a fancy meter
Post by: Carole on Mar 27, 2023, 18:52:38
That's the one l have, Dark Sky Meter.