opacity_from_atten¶
- pycraf.atm.opacity_from_atten(atten, elev=None)[source] [edit on github]¶
Atmospheric opacity derived from attenuation.
- Parameters
- atten
Quantity
Atmospheric attenuation [dB or dimless]
- elev
Quantity
, optional Elevation [deg] If not None, this is used to correct for the Airmass (via
airmass_from_elevation
; AM = 1 / sin(elev)), which means that the zenith opacity is inferred.
- atten
- Returns
- tau
Quantity
Atmospheric opacity [dimless aka neper]
- tau