The DRMI lock stability is improved. It can be locked for more than 10 minutes.

• Still 1f signal for SRCL is used. (3f for PRMI)
• I tried to implement ASC. The BS ADS with POP90 is easily implemented, PR3 as well. However, SRM or SR3 is not.
• AS_WFS_RF28 seems to be one candidate for the DRMI ASC. That sensor could sense the BS motion. I will check about SR3.
• Anyway, even without any ASC, the DRMI stability seems to be good enough for the DARM/CARM lock acquisition. I will spend one more day for DRMI ASC, and then we will moved on the whole RSE lock acquisition.
• The attached figure is the POP90 and AS34 corredponding to sideband power of f2 in PRMI and f1 in DRMI, respectively. First one is long term time series, and second is the one of one shot. This is just my feeling but the buildup sidebnad fluctuation isstabler than before.