Register to reply

How to find FWHM?

by bugra
Tags: aperture, fwhm, gaussian, photometry, stdev
Share this thread:
Jan31-11, 10:21 AM
P: 2
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,
Phys.Org News Partner Astronomy news on
Mixing in star-forming clouds explains why sibling stars look alike
Thermonuclear X-ray bursts on neutron stars set speed record
How can we find tiny particles in exoplanet atmospheres?
Feb1-11, 08:53 PM
Sci Advisor
HW Helper
EnumaElish's Avatar
P: 2,481
If you do it both ways, and the answers are different, what does that tell you about the fitting algorithm that you used?
Feb9-11, 07:03 AM
P: 2
for multiple sources on the same frame, should fwhm be same?

Feb10-11, 10:31 PM
Sci Advisor
HW Helper
PF Gold
chemisttree's Avatar
P: 3,724
How to find FWHM?

I would think the actual value of FWHM is less important than the rate of change near perfect focus.

Register to reply

Related Discussions
Sodium Iodide Detector (NaI) FWHM and applied Voltage Electrical Engineering 2
Can Raman Spectrum evaluate by FWHM? Atomic, Solid State, Comp. Physics 0
FWHM of a gaussian function Set Theory, Logic, Probability, Statistics 1
Converting laser fwhm bandwidth in m to hz Advanced Physics Homework 3
FWHM of radioactive sources confusion Advanced Physics Homework 4