L. Dartez, E. Goetz, J. Kissel

Yesterday's test results and plots show that 
(a) Installing one additional copy of the existing 65 kHz to 16 kHz "Dec16k" filter improves the 20-2000 Hz band aliasing dramatically, where as that *and* one additional copy of the 524 kHz to 65 kHz "Dec65k" filter does not significantly improve the 20-2000 Hz band aliasing (but one copy is still required). See LHO:82405
(b) We have (just barely) enough phase margin in the DARM loop to install more digital anti-aliasing. (I plan to make better plots today, but see page 1 of 4th attachment of LHO:82387)
(c) We have (just barely) enough CPU clock-cycle turn-around time to install a few more filters (see 2nd attachment of LHO:82375). If this proves problematic, we can start clearing out test filters to claw back computation time.

As such, we plan to move forward with installing an additional 65k to 16 kHz "Dec16k" filter in the primary GW-channel, 524 kHz, DCPD A0 and B0 banks tomorrow.

We happen to be unlocked now, so I've staged (loaded in, installed, but NOT turned off) the new additional filter in the A0 and B0 bank into the H1IOPOMC0.txt foton file.

While there, I took the time to improve the name and clarity of the A0 and B0 filter banks, much like I've done in the A1, A2, B1, B2 test banks (in LHO:82313),
    - Renamed "NewV2A" and "NewAW" in the A0 and B0 banks -- which are *different* filters, to compensate for the *different* analog electronics in those PDA and PDB chains -- to 
         . "PDA_V2A" and "PDA_AW" 
         . "PDB_V2A" and "PDB_AW" 
    - Split out the gain that was in "cts2V" = gain(0.0006105)*gain(0.25)*gain(0.25) into two banks "18b_cts2V" and "sum4avg"
         . For the "18b_cts2V" gain, even though gain(0.0006105)*gain(0.25) = gain(0.000152625) which DOES NOT equal the "right" gain of 40/2^18 = 0.000152587890625, (a ratio of 1.0002432, or 0.24% different). In the spirit of moving stuff around without changing anything I installed the a gain(0.000152625) for now. Also, at the 0.24% level, the channel to channel gain is probably different anyways, and comes out to some make-shift value anyways in the 4-channel averaging. The "not right" gain comes from the typo of 40/2^16 = 0.0006103515625, which was installed as 0.0006105.
         . The "sum4avg" is the gain(0.25) you would expect to turn the sum of 4 channels into an average.
    - Moved the "18b_cts2V" , "sum4avg" and "A2mA" gains to be in FM3, FM4, and FM5
    - Such that now there's a "Dec65k" in FM8, and two copies of "Dec16k" in FM9 and FM10.

Also -- since the H1:OMC-PI_DOWNCONV_INMTRX matrix is configured to use only DCPD A, I made similar changes OMC PI DOWNCONV SIG bank, except -- in tthe event we ever need to switch the sig bank over to DCPD B, I installed the "PDB_V2A" and "PDB_AW" filters there as well.

See attached screenshots.
    (1st) Screenshot of the A0 and B0 banks *before* any changes were made

    (2nd) Screenshot of the A0 and B0 banks *after* the changes described above were made. NOTE that FM10 is turned OFF.

    (3rd) Screenshot of the OMC PI DOWNCONV SIG bank *after* the changes.

    (4th) Screenshot of SDF accept of new arrangement of A0 and B0 filters.
    
    (5th) Screenshot of SDF accept of new arrangement of OMC PI DOWNCONV SIG filters.

The updated filter file is commited to
    /opt/rtcds/userapps/release/cds/h1/filterfiles/H1IOPOMC0.txt        rev 30480

The updated safe.snap (which is linked to both the safe.snap and OBSERVE.snap) has been committed to
    /opt/rtcds/userapps/release/cds/h1/burtfiles/h1iopomc0/safe.snap       rev 30481