more experimentation required …

Forums Spectroscopy Relative Flux Calibration more experimentation required …

Paul Luckas

Thanks Andy,

Yes, these discussions have got me thinking again because of the pro-am stuff that I’ve been involved in where using AOD was mandated simply because of the cadence requirements of rapidly changing features and the inability to acquire sufficient reference spectra often enough as the target moved through different altitudes. As Robin has mentioned, it’s also a usual technique used by professionals. 

However, I’ve never been totally at home with its implementation in ISIS – having witnessed some weird effects that could only be corrected with bizarre AOD values. So, more often than not, I revert to the standard practice of obtaining nearby reference star spectra to correct for instrument response and extinction – particularly when taking just an hour’s worth of spectra or so. The problem it seems, at least for me, is when to use one vs another, and applying some consistency to spectral processing (which seems more important).

Thanks for the contributions to this interesting dissection. Response and extinction correction in spectroscopy (and photometry for that matter) seem to be recurring themes, so there’s obviously some merit in all of this banter.