Author Topic: Sub Frame Selector  (Read 2026 times)

Offline rdryfoos

  • PixInsight Old Hand
  • ****
  • Posts: 377
Sub Frame Selector
« on: 2016 November 21 07:50:08 »
When I compare a drizzle integrated stack and a non drizzle integrated stack in SFS, the drizzle integrated stack has a FWHM way higher for the same data.  In order to to really compare FWHM, Eccentricity, noise and SNR between a drizzled and non drizzled image--should the pixel scale be changed (in system parameters) for the drizzled image? 

Thanks,

Rodd

Offline mschuster

  • PTeam Member
  • PixInsight Jedi
  • *****
  • Posts: 1087
Re: Sub Frame Selector
« Reply #1 on: 2016 November 21 16:04:35 »
When upsampling I think you can scale the FWHM measured in pixels by the upsampling factor for comparison purposes.

Eccentricity probably should be compared directly, ie no scaling.

SNR's are very much not comparable, due to the pixel correlation and pixel coverage image scaling.

Thanks,
Mike