Spectral whitening of AMBRE templates and SDSS spectra

In order to do spectral fitting of uncalibrated spectra, in advance, the spectral whitening applies to spectra. We try a method in which Fourier transformation to a spectrum is performed and then a bandpass filter is applied to it. We use AMBRE templates and observed SDSS stellar spectra for this study. 

This ticket includes the application method to those spectra. Evaluation of the results and the fine tuning of a width of a bandpass filter will be covered in a ticket for spectral fitting.