Algorithm used to calculate line centre in ISIS

[Robin Leadbeater]

What algorithm does ISIS use to calculate the wavelength of a line? It does not appear to use the barycentre or the median or a Gaussian fit.

Thanks
Robin

[Christian Buil]

Hi Robin

ISIS use a multiparameter gaussien fit (FWHM, peak intensity, positition, background) for measure line profile.

Christian

[Robin Leadbeater]

Thanks Christian,

I tried ISIS again and this time the results were correct for a Gaussian fit. I am not sure why I got a different answer when I tried it before.

Robin