Tilt in LBC Red
Analysis of extra-focal 4-chip images taken on 20111210 indicates some tilt in LBC-Red.
There are 5 extra-focal pupil images analyzed for Blue and Red: 3 with PA=0, Rotator Angle ~ 0
and 2 with PA=180, Rotator Angle ~ -180 degrees.
LBCFPIA was run on subsections of these images, but editing the LBCChip and ImgSec
in the lbcfpia.cfg
file (I added and uncommented these lines).
There are scripts: focus.idl and focus2.idl which, for a single image, edit the cfg files and output
"Median External Diameter" for each of 12 subregions of the science field (3 subregions per chip).
For Red PA=0 data, there is a clear trend toward larger diameters towards the bottom right, with
a maximum of 6 pixels greater than the center.
For Red PA=180 data, this is not exactly reproduced.
See the attached LBTtilt files (pdf is not formatted correctly --- have to correct).
- 18 Dec 2011