Update background subtraction algorithm in BANZAI-NRES

LCOGT / banzai-nres

BANZAI Data Reduction Pipeline for NRES

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Update background subtraction algorithm in BANZAI-NRES #117

Open markBowman opened 17 hours ago

markBowman commented 17 hours ago

As an NRES developer, I would like to be able to better subtract the background to remove data artifacts due to scattered light so that we can produce reliable radial velocities.

[ ] Add a dilation step to get a background data section for each order
[ ] fit a smooth b spline to the background section
[ ] fit gpflow to the background section
[ ] compare the results
[ ] deploy the better of the two algorithms

markBowman commented 17 hours ago

This is time boxed to 2 points. The current background technique does ok in the blue, but in red orders fails to the point of concern. I expect to try two more methods for the smooth background component:

dilate the traces mask and use small subsections to fit a smooth b-spline Try a SVGP using gpflow https://gpflow.readthedocs.io/en/master/notebooks/advanced/gps_for_big_data.html. This may also need to use a subset of the data to be feasible.