- Kevin Stevenson
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|General Updates||Nikole Lewis|
|TSO Branch of Pipeline Overview||Nikole Lewis|
|'Optimal' CalTSO3 Photometry Procedure Proposal||Everett Schlawin, Jonathan Fraine|
Multiple methods of background subtraction available to users in the pipeline.
Four methods of centering. For out of focus data, flux-weighted centering misses the target by a pixel or two. Gaussian centering is precise but very temperamental.
Take a median image and MAD image and compare to flag cosmic rays through the data cube.
|'Optimal' CalTSO3 Spectral Extraction Proposal||Kevin Stevenson|
Compared results from spectral extraction methods in CALTSO3 pipeline
Added hot pixels and cosmic rays to test
Basic: Sum along column
Standard: Sum fluxes within 16 pixels of trace
Optimal: Weighted spectral extraction (Horne 1986)
Make a stack from all images and make a median image from which to get a trace mask.
Made a mask for the traces and used the rest for background subtraction
The choice of spectral extraction dilutes the white light transit depth predicted by the model
Standard and optimal methods are equivalent if bad pixels are removed. Optimal is necessary and safest way if cosmic rays are present.
“Columns of Death” are a symptom of a moving bias across the frames.
2 column wide defect that moves one column each integration.
Weaker for NIRISS, pronounced in NIRSpec
Tracked by the reference pixels so could be subtracted. At what step in the pipeline though?
Loic says a rolling reset can be used on NIRISS, resetting 1/4 ramps before each integration.
Spectral Extraction Code
Location of NIRISS/SOSS data: https://www.dropbox.com/s/tisfrbjmur7d5hg/datagen_hd209.tgz?dl=0