[#PIPE2D-1136] Correctly subtract the dark signal seen on r3

[PIPE2D-1136] Correctly subtract the dark signal seen on r3 Created: 22/Dec/22 Updated: 22/Feb/23 Resolved: 06/Jan/23
Status:	Done
Project:	DRP 2-D Pipeline
Component/s:	None
Affects Version/s:	None
Fix Version/s:	None

Type:

Story

Priority:

Normal

Reporter:

rhl

Assignee:

rhl

Resolution:

Done

Votes:

Labels:

None

Remaining Estimate:

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Time Spent:

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Original Estimate:

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Attachments:

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Issue Links:

Relates
relates to	~~PIPE2D-1169~~	Capture r3 glow notebook, scripts and...	Done

Reviewers:

price

Description

There is a bright defect in the r3 camera which doesn't subtract out well with the dark frame processing, presumably because its amplitude varies with time.

Please change the code to estimate the amplitude of the defect based on the part of the CCD where there are no fibre traces.

Note that this cannot, in theory, simply be done by adjusting the amplitude of the dark frame as there may well be a stable and unstable component. An interesting experiment would be to carry out a PCA decomposition of the darks and measure the dimensionality of the needed solution.

Comments

Comment by rhl [ 22/Dec/22 ]

An example is 83149

Comment by hassan [ 22/Dec/22 ]

Attached calexp images (with and without corrections for the dark current) of r3 and m3 visits showing the abnormality.

Comment by rhl [ 29/Dec/22 ]

https://github.com/Subaru-PFS/obs_pfs/pull/142

Comment by rhl [ 29/Dec/22 ]

See https://sumire-pfs.slack.com/archives/C3AU3VCMU/p1672247056447469 for illustrations of successful testing of this code.

Comment by rhl [ 04/Jan/23 ]

N.b. The code assumes that there are no bad pixels in the dark. This needs to be fixed (maybe in a different ticket); although we don't want saturated pixels in the darks they may happen and then both the dark generation and the code that uses the darks need to be modified.

Comment by rhl [ 06/Jan/23 ]

As discussed on slack, we won't worry about versioning the BBoxes just yet.

Also added code to handle masked pixels in darks and data, contrary to remarks made in my previous comment.

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[PIPE2D-1136] Correctly subtract the dark signal seen on r3 Created: 22/Dec/22 Updated: 22/Feb/23 Resolved: 06/Jan/23