Re: [Phys-L] Statistics question

[brian whatcott <betwys1@sbcglobal.net>]

On 8/24/2012 1:35 PM, Paul Nord wrote:
> Do you say "half-width" or Full Width at Half Max (FWHM)?  And what does it mean?
>
> <quickly withdrawing hand from piraña tank>
>
> Paul
A popular use of the term  FWHM is in the field of optics and in respect 
to star images in particular.

It happens that one useful way of arriving at this number is to generate 
a (normalized)
 radial intensity function,  for a wide range of  star intensities s in 
a field, and find a
 best fit to a Gaussian. This has something to tell about optical 
quality &  seeing -
 i.e the point spread function.   The radial intensity is by its nature 
a half width graph,
so one is offered the chance of deriving full width numbers by radial 
(half width ) data.

This could cause confusion, possibly?

Brian W