get_resolution

sofia_redux.instruments.exes.get_resolution.get_resolution(header)[source]

Retrieve expected spectral resolving power.

Requires spectral resolution files in exes/data/resolution for overriding cross-dispersed resolutions:

  • short_wave_resolution.txt

  • medium_wave_resolution.txt

  • long_wave_resolution.txt

These files must have 2 columns: slit width (arcsec) and spectral resolving power (lambda / dlambda). The file chosen is based on the central wavelength for the observation.

The procedure is:

  1. Read resolution data from the configuration file matching the central wavelength of the observation (WAVECENT).

  2. Use SLITWID to find the closest resolution value.

  3. If no appropriate data is found, or the mode is not cross-dispersed, the value of the RP (if present) or RESOLUN keyword is returned. Otherwise, the best matching resolving power is returned.

Parameters:
headerfits.Header
Returns:
float

Expected resolving power.