I constructed a master bias frame and a master g flat frame for DECam images of Starlink satellites taken in early March 2020. These are the notes I made for how to do this.

 
How to process some raw DECam images 101

• you need raw biases, raw flats, and raw images, and a setup stack
• put a _mapper in a directory to turn it into a repo, and cd to there
• make raw, calib, and calib_construction subdirectories
• put all the raw images in the raw subdirectory
• examine the raw image headers with, e.g., fitsheader or queryMetadata to learn their visit numbers
• ingestImagesDecam.py . --mode=link raw/*
• ingestCuratedCalibs.py . --calib calib $OBS_DECAM_DATA_DIR/decam/defects
• ingestCuratedCalibs.py . --calib calib $OBS_DECAM_DATA_DIR/decam/crosstalk
• constructBias.py . --calib calib --output calib_construction --id visit=biasVisit1^biasVisit2^biasVisitN --batch-type none
• ingestCalibs.py . --calib calib --mode=link --validity 999 calib_construction/BIAS/[date]/*.fits
• constructFlat.py . --calib calib --output calib_construction --id visit=flatVisit1^flatVisit2^flatVisitN --config isr.doDark=False --batch-type none
• ingestCalibs.py . --calib calib --mode=link --validity 999 calib_construction/FLAT/[date]/[filter]/*.fits
• make a ref_cats subdirectory and add symlinks to pan-starrs and gaia-dr2 refcats as usual
• processCcd.py . --calib calib --rerun [rerun] --id visit=visit1^visit2^visitN --config isr.biasDataProductName='bias' isr.flatDataProductName='flat'
• WARNING: to get processCcd to work the first time, I had to manually update the calibRegistry and calib directory to get the filters right; I filed DM-24514 to eventually address this and in the meantime put a workaround as one commit on this ticket
• Note the default DataProductNames are cpBias and cpFlat for DECam, thus the configs
• It ... seems ... to be working ?!?!

I updated the notes above as I revisited the process and worked to revise obs_decam's ingestCalibs. I can successfully build obs_decam on lsst-dev with scons and have used it to ingest both CP and stack-built calibs.

Jenkins is in progress: https://ci.lsst.codes/blue/organizations/jenkins/stack-os-matrix/detail/stack-os-matrix/31658/pipeline 

An example of the stack-built calibs are on lsst-dev in /project/mrawls/starlink/calib_construction and the ingested results are in /project/mrawls/starlink/calib.

I finally have the tests done for this one. There are now 3 PRs.

I once again manually verified I can ingest both stack-built calibs and CP calibs on this ticket branch.

I also started a new (new) Jenkins run: https://ci.lsst.codes/blue/organizations/jenkins/stack-os-matrix/detail/stack-os-matrix/32158/pipeline 

Can you please look again John Parejko?

Addressed all comments on GitHub and started Jenkins: https://ci.lsst.codes/blue/organizations/jenkins/stack-os-matrix/detail/stack-os-matrix/32202/pipeline

Thanks for the updates and new tests. Now we have something to test future gen3 code against, too.