Sky spectrum is subtracted by interpolating adjacent sky spectrum.
This is a batch (CL) script doing IRAF background tasks for FOCAS
Standard fitting parameters (fitting order) is pre-defined within the task
After fwavecalib.cl
Before fsenscalib.cl
Data input: Object.fits (Output files of fwavecalib.pro)
Data output: Object_bg.fits (background-subtracted Object files)
Just follow the IRAF background task..