Twinkles Weekly: January 26th, 2017

The image differencing problem seems to have been traced to the template coaddition failing due to undersampled images - we’ll try restricting ourselves to images with IQ better than 2.5 pixels (0.5”). Bryce and Rahul are making progress on the error model, training it on Run 1.1 for application to Run 3, and have the upcoming meeting in mind. We resolved some small issues too.

Minor Issues

Image Differencing Update

We heard from Simon about the image differencing work #421, to see if we can help with any roadblocks.

When a visit image is close to undersampled the template coadd is corrupted; u-band is OK but the others are not. Simon suspects a bug, surprised that this is unstable. Short term fix is to select images for template coadd using both a minimum and maximum image quality. Lower bound seems to be (anecdotally) 2.5 pixels or so. Bryce has showed that DM measured seeing is systematically lower than opsim seeing in Run 1.1: we need to plot this for Run 3, which means we need an Object table, and this needs a new config.

Action: Simon to provide config from master ( #422 )

Workflow will need to be updated to include command line call that includes new command line config file. Related to this is the top level cookbook, which is our planned Note.

Action: Phil to start that note and get this moving.

NB the #421 issue thread is not being used to track progress… Could it be? We decided to try.

Error Model Analysis Update

We’ll check in on the development of the Twinkles error model against the Run 1.1 or Run 3 test data. There are no open issues except for a discussion of emulating calibration (#415) but there should be!

Action: Bryce: to “import” discussion issues from Monitor

Rahul and Bryce are working on getting Monitor fully merged and then implementing the error model plan. Both think thatr they have enough information from Run 1.1 to design and test a first go model and its code.

Live DESC Meeting Schedule Perusal

We looked at the upcoming meeting schedule together and decide in real time our plan of action. Thoughts: