Record telescope offsets

We current just record the "FITS.SBR.

{RA,DEC}" positions in the PFS FITS headers. Those are not the simple slew positions, and clearly include at least some telescope offsets: the values change continuously.

We need to do better. What component offsets are available from Gen2 (guide? manual?) and what are their coordinate systems? What does FITS.SBR.{RA,DEC}

actually represent? Is there a good example we should follow?

eric ?