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FWHM too big???
08-03-2007, 12:15
Post: #2
RE: FWHM too big???
No this is what you would expect. It is indeed true that the FWHM is equivalent to 2xFLUX_RADIUS for Gaussian profiles. But the SkyMaker PSF is not a Gaussian: it is a realistic model that takes into account the atmospheric MTF (exp(-f^5/3)), the instrumental diffusion (inverse square law in the wings), and convolution by the intrapixel response function (door function). In the end, the profile is far from a Gaussian, but it is realistic: to give you an example, for a 0.60" seeing on real MEGACAM images, 2xFLUX_RADIUS is measured at 0.72".
- Emmanuel.
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FWHM too big??? - lino - 08-03-2007, 11:48
RE: FWHM too big??? - Emmanuel Bertin - 08-03-2007 12:15

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