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mperrin / webbpsf

James Webb Space Telescope PSF simulation tool - NOTE THIS VERSION OF REPO IS SUPERCEDED BY spacetelescope/webbpsf
BSD 3-Clause "New" or "Revised" License
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WebbPSF-WFIRST_Tutorial example misleading #156

Closed rubab1 closed 6 years ago

rubab1 commented 7 years ago

The worked examples here linked from the STSci WFIRST WebbPSF page shows that 

mono_psf = wfi.calc_psf(monochromatic=1.2e-6)

has EE50 = 0.069" and FWHM = 0.138" whereas WebbPSF built in functions calculate approximate EE50 = 0.082" and FWHM = 0.105". 

import webbpsf
import webbpsf.wfirst
wfi = webbpsf.wfirst.WFI()
mono_psf = wfi.calc_psf(monochromatic=1.2e-6)
webbpsf.measure_fwhm(mono_psf)
0.1047605318024962
getEE = webbpsf.measure_EE(mono_psf)
getEE([0.069,0.08,0.082,0.084,0.086])
array([ 0.43128342,  0.4948787 ,  0.50307424,  0.50997386,  0.51562519])

The mismatch is significant in context. Apparently the mismatch is due to the webbpsf.display_profiles() function using sparsely sampled radial profile and EE to estimate EE50, then setting FWHM = 2*EE50.

josePhoenix commented 7 years ago

Hi @rubab1, @mperrin and I agree this isn't how the FHWM annotation should work. The implementation is not in WebbPSF, but rather in mperrin/poppy if you would like to open a Pull Requestâ„¢.

P.S. Say hi to @meredith-durbin for me 😄

mperrin commented 6 years ago

Issues migrated to https://github.com/spacetelescope/webbpsf/issues. Please see the copies in that repo from now on.