Beam spot sizes are wrong for Advanced LIGO

@gabriele-vajente writes:

looking at the pygwinc code to compute thermal noise, I noticed that the beam spot sizes are wrong for Advanced LIGO. It looks like the RoCs of ITMs and ETMs are wrong.

From https://git.ligo.org/gwinc/pygwinc/blob/master/gwinc/ifo/aLIGO/ifo.yaml:

• ITM = 1970 m
• ETM = 2192 m

but from design and measurements the right numbers are

• ITM = 1934 m
• ETM = 2245 m

This results in the beam size on the ITM to be wrong: pygwinc uses 55mm, while the actual number is 53mm