… Always use AOD for reference spectra processing.
Use AOD on target spectra only if reference spectra taken at a different time / altitude.
Do not use AOD on target spectra if reference spectra taken at same time / altitude as target.
Edit: Apologies, it was late. What I mean’t to say, and what I think is correct:
If AOD is enabled when processing reference spectra, ensure AOD is also enabled when processing target if using this “AOD corrected” reference.
Do not enable AOD when processing target spectra if reference spectra (taken adjacent to target) has not been AOD corrected.
If reference spectra has been AOD corrected (ie, it is IR only) then target spectra that it is applied to needs to be second order corrected using AOD.