Defining Pointing Terminology

There has been a lot of confusion about pointing terminology.

• CSO pointing model: the telescope pointing model used and written as a black box


• has already been corrected for aberration/nutation


• is in current epoch coordinates (e.g. J2007.34)


• Instrument-specific correction to pointing model


• ??? also referred to as 't terms'


• is offset between CSO pointing model and real locations


• should be a function of alt (and maybe az)


• is recorded in "RPC" files


• is in units of distance on the sky: delta-RA and delta-DEC, or delta-ALT and delta-AZ will be in the same units, while if they were in coordinate units delta-RA and delta-AZ would have to be scaled by 1/cos(DEC) or 1/cos(ALT) respectively
  


• FAZO and FZAO: Fixed Azimuth Offset and Fixed Zenith Angle Offset
  
  • these are ambiguously defined in the pipeline code
  
  
  • ???? FAZO/FZAO include both the functional instrument specific pointing offset and any manual changes made at the telescope [manual only relevant to 2007 observations]
  
  
  • ???? or are these JUST fixed offsets, and the instrument specific corrections are not included? Either way, how can I separate out manually-applied fixed offsets from fitted-model offsets?