Unihedron

General Category => General Discussion => Topic started by: dklinglesmith on November 27, 2014, 04:08:16 am

Title: Naked Eye Limiting Magnitude
Post by: dklinglesmith on November 27, 2014, 04:08:16 am

I have a simple python script running for the SQM-LR.  Still need to generate a nightly graph.

How is the Naked Eye Limiting Magnitude calculated?  I did not see it coming back from the instrument.

cheers, Dan Klinglesmith

Title: Re: Naked Eye Limiting Magnitude
Post by: admin on November 27, 2014, 12:38:59 pm

Quote from: dklinglesmith on November 27, 2014, 04:08:16 am

I have a simple python script running for the SQM-LR.  Still need to generate a nightly graph.

How is the Naked Eye Limiting Magnitude calculated?  I did not see it coming back from the instrument.

cheers, Dan Klinglesmith

Hi Dan,

NELM calculation can be found here:
  http://unihedron.com/projects/darksky/NELM2BCalc.html (http://unihedron.com/projects/darksky/NELM2BCalc.html)

NELM=7.93-5*log(10^(4.316-(Bmpsas/5))+1)


Or using this chart which also depicts the not so precise conversion to NELM because of differences in human vision:

(http://unihedron.com/projects/darksky/images/MPSASvsNELM.jpg)


Cheers,
Anthony

Title: Re: Naked Eye Limiting Magnitude
Post by: kyba on November 28, 2014, 01:02:55 pm

Hello Dan,

I just wanted to let you know that if you'd like to share your data with researchers, it is best to store it in the community standard format that we developed two years ago: http://www.darksky.org/night-sky-conservation/248

If you are interested, Kai Pong Tong from Bremen has a Python script to read out an SQM and print the header and information in the standard format that he would be willing to share with you. If you are interested, please send me an email. My contact information is here: http://userpage.fu-berlin.de/~kyba/

Christopher Kyba

Title: Re: Naked Eye Limiting Magnitude
Post by: dklinglesmith on December 01, 2014, 06:05:45 am

thanks for the information and links.

cheers,
Dan Klinglesmith