IFU Coordinates
IFU coordinate calculation is horrible the stepsize per pixel is off by about an order of 200 and it is not clear where where the center coordinates reference off or what the angles mean.
The calculation in kis_tools.gris.ifu_fits_file.IFUFitsFile._coords_from_simple_header
need to be completely re-written or at least validated.
I don't have time to do this now as we need to get IFU data running for the V1 release, so the best I can do is to increase the uncertainties to a full solar disk and issue a warning each time the function is used.