J. Kissel, J. Betzwieser, M. Wade, C. Cahillane

After finally getting the LHO GST-LAL, GDS, Low-Latency pipeline up and running, we noticed that the reconstruction of DARM_ERR and DARM_CTRL that is shipped over to CAL-CS and stored in the frames was corrupted by numerical precision errors. We had been using the same whitening filter that's used for the DELTA L RESIDUAL, CTRL, and EXTERNAL channels, i.e.
    zpk([1;1;1;1;1],[100;100;100;100;100],1,"n")
but that *over* whitens DARM CTRL and DARM ERR. As such, I've changed the filters to what LLO has installed, a less aggressive,
    DARM_ERR = zpk([10;10],[100;1000],1,"n")
    DARM_CTRL = zpk([5;5],[500;500],1,"n")
I attach two sets of plots:
(1) Bode plots of the new filters, and
(2&3) Courtesy of Joe, Comparison between the raw ASDs of DARM control for a recent lock stretch, and that which is whitened with the above mentioned filters.