scopesim.effects.metis_lms_trace_list.echelle_setting

scopesim.effects.metis_lms_trace_list.echelle_setting(wavelength, grat_spacing, wcal_def)

Determine optimal echelle rotation angle for wavelength.

Parameters:

• wavelength (float) – central wavelength in microns

• grat_spacing (float) – grating rule spacing in microns

• wcal_def (fits.TableHDU, fits.BinTableHDU, Table, str) – definition of the wavelength calibration parameters If str, interpreted as name of a fits file, with a table extension ‘WCAL’.

Returns:

• a dict with entries

• - `Ord` (echelle order)

• - `Echelle` (echelle angle)

• - `Phase` (phase)