Calibrating and stacking spectra?

[Gasman]

Hi guys
I`m now taking spectra using a slit type spectroscope that only shows the spectrum of the star and doesn`t show the star itself, a grab of a spectrum taken of P Cyg the other evening is attached. I`m trying to find a way for PI to stack and calibrate these fits files but the batch preprocessing script is looking for a minimum of 6 stars which obviously are not available with these spectrum files and I wonder if there is another way I can stack/align these with PI please?
thanks
Steve

[TobiasLindemann]

Hi Steve,
calibrating should be no problem. Activate the checkbox "calibrate only" in the BatchPreprocessing. As you know "StarAlignment" registration don't work, because you have no stars. Have you tried the "FFT-Registration", which you can find in "scripts->utilities". I have tried this with your jpeg and two shifted versions of it and it worked.

Greetings
Tobias

[Gasman]

Hi Tobias
Many thanks for the info. Not sure what happens with FFT-registration but the resulting profiles of 10 betaLyra spectra and 10 PCyg spectra (blue in the attachments) have much smoother profiles than without so looks a very useful tool 
cheers
Steve

[TobiasLindemann]

You are welcome.
Nice spectra :-)