Example run:

python bin/convert-frame --frame frame.fits --cframe spCFrame-b1-00121278.fits --wa --out frame-b1-00121278.fits.gz

This will create the frame-b1-00121278.fits.gz file following the DESI brick conventions:

• HDU0: flux
• HDU1: ivar
• HDU2: mask
• HDU3: wavelength
• HDU4: resolution
• HDU5: fibermap

The wavelength is determined by HDU3, fiber 250 (or 750) in the --wave file. Everything else is interpolated to this grid.

The flux is the sum of the flux and sky as read from the frame file (to allow the user to run a sky subtraction).

The resolution is gaussian with a dispersion given by wdisp.

The spCFrame is needed to read the wavelengths (and the fibermap, although this info is also in the spFrame file).