Users Guide to Phase Referencing

7/20/99, bfl

Setting Up

Switch the PZT stroke to the SDL; find the power supply at the bottom of the right-most cardcage, find the switches labeled "SDL stroke" and "LDL stroke". Turn off the LDL, turn on the SDL.
Select and appropriate integration time script and run it - e.g. 10250MS (10 MS primary, 250 MS on secondary). Reboot both fringe trackers, do cal low, cal high.
Open up the SDL delay line gui, go to update constants, swap the CT and SDL channel settings: When Phase Referenced: SDL: Slow, 1, 1, Slow, 2, -1. CT: Slow, 3, -1, None, -1, -1.
Align the CT, get a good signal, leave it on.
Stroke Set the SDL, using values from the PRIMARY FT.
Set and send modulations to both LDL and SDL, take values from the SECONDARY FT, and make the amplitude NEGATIVE for the SDL, POSITIVE for LDL. Make sure your choose the "sawtooth" waveform (2nd from right).
In FT1 constants window set SNR Thresh Slp: 0.05, 0.05, 0.04. and set Data Rec Backoff = 2. Also set the gain to 0. Finall set the Kalman Filter parameters to 0, -1, 0.25, 0.1.
Rlogin to seq, set bSeqDualHasBrightSecondary=0, and set dlOkThresh=120.0
Rlogin to ft0, set intermediateUpdateFlag=1. (check bPosFeedForward=1, overlappingUnwrapperFlag=1)
Put CT filterwheel in computer mode.
Run just as for dualstar. Note that the locks offsets change when you switch to faint star mode: If "PL" is primary lock offset, "SL" is secondary we have: PL -> PL, SL -> SL - PL.

ben@huey.jpl.nasa.gov