Please see the source code for details. All Rights Reserved. Please see the source code for details. The idea was that if we indeed have indents in the race you would be able to see the upper housing drop in to them. Detection of central bearing flaws was quite clear at all known locations, yielding deflections of about 20-40 microns with a width of around 3 degrees.
Several options are available.
I would tend to dismiss a single 'big lump' or trough as this would not very well explain equal sized tilts of the housing in opposite senses 180 deg apart in azimuth. The effect on pointing is entirely due to torque, so probably does not care too much which particular top or bottom flaws are lined up at any given time. To first order I would imagine the tip of the bearing will have negligible effect in elevation as the motion does not get transmitted via the A-Frame members. This may explain the non-linear baseline noted by IMC in the latest data though.