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kammerje / spaceKLIP

Pipeline for reducing JWST high-contrast imaging data. Published in Kammerer et al. 2022 and Carter et al. 2022.
https://ui.adsabs.harvard.edu/abs/2022SPIE12180E..3NK/abstract
MIT License
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update docs: clarification of the various alignment functions #176

Open mperrin opened 1 month ago

mperrin commented 1 month ago

The following info would be nice to include in the readthedocs, paraphrased and cleaned up suitably. From #153:

@AarynnCarter:

Redundancy in recenter_frames, update_nircam_centers, and align_frames()? Not clear to me what the difference is between these functions.

@kammerje:

The alignment function should be enough to align all subsequent frames in a concatenation to the first frame in that concatenation. KLIP should work after that. However, you will be assuming that the star position (KLIP center) is the CRPIX position in the header which is what we have done for MIRI, but not for NIRCam. For NIRCam, the recentering function finds the position of the star using WebbPSF_ext models, and then centers the first frame of a concatenation on the position of the star, before running the alignment, so that the KLIP center is more accurate. The update centers function was only required while the CRPIX values in CRDS were still wrong in the beginning of the mission. Now it should be redundant, but let's not throw this function out because we might want to reprocess old data. All three functions have their right to exist.