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 “integration_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.

• --interpolation

This is a string that specifies how to interpolate between pixels of the input data. The default value is “nearest”, which means that no actual interpolation will be done; the pixel number will be rounded to an integer, and the input value at that pixel will be used.

This argument is not currently used. It is included as a placeholder for a possible future enhancement.