We've already had three different flat sets generated during Y3N, due to the camera warmups, how do they compare?

Michael J has processed the dome flats and generated 3 epochs of superflats spanning these ranges of dates:

  1. Reference epoch: 20150731-20150804
  2. Epoch 2: 20150813-20150818
  3. Epoch 3: 20150828-20150904

Robert G has subtracted Epoch 2-Reference Epoch (left panels) and Epoch 3-Reference Epoch flats (right panels) from each other, and here are .pngs of the differences.

The flats were pre-normalized to 1.0 prior to subtraction, the differences represent a fractional change which can be seen in the scale bar at the bottom for each filter.

Darker shades are 'lower', Brighter shades are 'higher' flat counts, compared to the reference epoch.

u-band udeltaflat.png

g-band gdeltaflat.png

VR-band VRdeltaflat.png

r-band rdeltaflat.png

i-band ideltaflat.png

z-band zdeltaflat.png

Y-band Ydeltaflat.png

Robert's inputs fits images are at: https://deslogin.cosmology.illinois.edu/~rgruendl/Y3N/

In each picture, CCDNUM = 2 is to the left, CCDNUM = 61 is to the right, CCDNUM = 31 is the split CCD on top.