Step Arguments

The combine_1d step has two step-specific arguments:

--exptime_key

This is a case-insensitive string that identifies the metadata element (or FITS keyword) for the weight to apply to the input data. The default is “exposure_time”. If the string is “effinttm” or starts with “integration”, the integration time (FITS keyword EFFINTTM) is used as the weight. If the string is “effexptm” or starts with “exposure”, the exposure time (FITS keyword EFFEXPTM) is used as the weight. If the string is “unit_weight” or “unit weight”, the same weight (1) will be used for all input spectra. If the string is anything else, a warning will be logged and unit weight will be used.

--sigma_clip

Optional factor for sigma clipping outliers when combining spectra. If a floating point value is provided for sigma_clip, this value will be used to set an outlier threshold for any pixels in the input spectra that deviate from the median and median absolute deviation of the inputs. Defaults to None (such that no clipping is performed).