DescriptionΒΆ
jwst.assign_mtwcs is run in the beginning of the level 3 JWST pipeline.
It assigns a WCS to a Moving Target exposure. The table below defines the
keywords specific to exposures with moving targets:
FITS keyword |
Data model attribute |
Type (Value) |
Description |
|---|---|---|---|
TARGTYPE |
meta.target.type |
string (moving) |
Type of target |
MT_RA, MT_DEC |
meta.wcsinfo.mt_ra, meta.wcsinfo.mt_dec |
number, number |
Average right ascension and declination of the moving target during exposure [deg] |
MT_AVRA, MT_AVDEC |
meta.wcsinfo.mt_avra, meta.wcsinfo.mt_avdec |
number, number |
Right ascension and declination of the moving target averaged between exposures [deg] |
The step takes the original science WCS pipeline and adds another step to it such
that the output_frame of the final WCS is centered at the average location of
the moving target specified by (MT_AVRA, MT_AVDEC).
The transform of original WCS associated with the science aperture pointing can be accessed by executing:
sci_transform = model.meta.wcs.get_transform('detector', 'world')