= Summary =
I calculated the Schnupp asymmetry from the yesterday's measurements.
The result is: l_asym = 1.33(7) m, although the designed value is 3.3298 m.
I do not yet know why they do not coincide. I will re-do the measurement once the interferomter gets healthy.

= Detail =
-- Simple average of the TF measured yesterday is: 0.027(2) nm/cnt
-- This can be converted to m/Hz as: (δl_MICH / δf) = TF_measured * 10^-9 / ( V2cnt conv. * A_aom) = 0.027 * 10^-9 / (5.71 * 10^-4 *  10.02 * 10⁶ )
-- l_asym =  (δl_MICH / δf) * f_laser = 0.027 * 10^-9 / (5.71 * 10^-4 *  10.02 * 10⁶ ) * (3*108 / 1.064*10-6) = 1.33 m
-- Dominant error source is from the TF measurement, so l_asym = 1.33(7) m
-- Note on polarity: positive excitation in feedback signal to AOM gives positive frequency shift after AOM, and that results in negative frequency shift of main laser via RefCav loop, and then that is equivalent to negative displacement of l_mich if l_x > l_y.
Recalling current calibrated displacement channel moitors -l_mich, measured TF should be positive. The polarity is correct, accoriding to the phase of TF measured yesterday.

= Possible reason why they do not coincide =
-- Optical gain might have changed so much. --> I will repeat this TF measurement when IFO is quiet.
-- My calculation might be wrong --> Can someone do double checking???
-- Length between ends and center area might be wrong --> quiet unlikely.