Find FWHM: Pixel Values, Gaussian Curve, Standard Deviation

  • Context: Undergrad 
  • Thread starter Thread starter bugra
  • Start date Start date
  • Tags Tags
    Fwhm
Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
Sign up Log in
3 replies · 6K views
bugra
Messages
2
Reaction score
0
Hi,
I've been searching on google for minutes but couldn't find out a consistent way so far. I mean, it seems everybody has something to say about it :)

My data consists of pixel values (ADU's). I am writing a script to obtain fwhm of seeing disk.

By definition of the gaussian curve, i should only calculate the standart deviation of these values theni get fwhm=stdev*2.355 .
Am I correct?

Or should i obtain a gaussian fit then i calculate fwhm as its name suggests?

Thanks in advance,
bugra
 

Discussion

Astronomy news on Phys.org
If you do it both ways, and the answers are different, what does that tell you about the fitting algorithm that you used?
 
for multiple sources on the same frame, should fwhm be same?
 
I would think the actual value of FWHM is less important than the rate of change near perfect focus.