To Start
-Laser is on. All ND filters are out. Polariser is in.
-In opttab2: srcin, inpin, refin, monout, all shutters open
 (could have wdsin and edsin for now), [selout]
-Small (10mm) apertures in.
-Wobblers are on (up to 72.5V)
-Double-target is on exit from BRT
-Sids have mirror heaters and bins removed, rooves closed.
-LDC is set to zero total optical dispersion position (2 5)
-Laser spots appear on double target. If not will need to check the 
 alignment down the rails.
Launch laser to BRT exit
-Plug PHP (Pico-motor HandPaddle) into port #55 at BRT, remove short
 grey patch cable from #55 first.
 Adjust Drivers 6&7 to centre spots on double target.
 [PHP use:   Component      Driver(S,N)  Speed
           Beamsplitters     1,2          10
           Reference         3            10      motor A = elevation
           Autocoll mirrors  4,5          10      motor B = azimuth
           WC OPLC mirrors   6,7          10      motor C = el for 6,7 temporarily
           South metrology  10,11          2
           North metrology  12,13          2
  Connect PHP to any port in enclosure. On south electronics in control room
  rack take cable marked 'Hand terminal for picomotors' and plug other end
  into the port where PHP is.
  PHP speeds: do 'shift-speed' and enter a value. Use 2, 10, 50 or 200]

-Check the beam is centred on the catseyes small targets. If not, you'll 
 need an alignment down the rails.

-Reconnect short grey patch cable

These next five steps optional (alignment thru the BRT)
-Take a rail alignment tool and place it in front of the north beam part
 of the large BRT double target.
-Remove the large BRT double target and look at the beam on the vacuum pipe windows.
-If required, move the EC PLC mirror for the north beam (note beams crossover!)
 to centre beam on the vacuum pipe window (NB this should be done to 0.5 mm
 accuracy if possible for long baselines). 
-Repleat last 3 steps for south beam.
-Slide the small autocolimation mirrors into place in front of the large BRT
 (needed for the next step).
Internal Autocollimation
The main point of this is to check that the reference beam is aligned as
accurately as possible but also to check that the wobbler injection
beamsplitters are roughly aligned.

 -Put the observing (28mm) apertures in.
 -Could turn on fluoros in south tunnel only for some light.
 -Place a large white card against the rod holders in front of the Celestron 
  (Don't touch the Celestron itself). Autocollimate the north and south beams
  using the PHP at port#52, (drivers 4,5) so that the return laser beams
  evenly illuminate both pupils at the entrance to the wobble2 camera.
  Centre the dark spot, and maybe check pattern at beamsplitter apertures
  to be sure. The fringes on the reference pupil will 'fluff out'.
 -Place some ND in front of the laser (say 2.3 + 1.3 + 1.5 [top-right labels])
  and switch lights off, taking PHP with you.
 -Look at the return beams with wobble2 in widefield mode. If there is more than
  2 pix of movement required for the N or S beams or 1 pix for the reference beam,
  then adjust the north and south beamsplitters (motors 1,2) or reference mirror (3)
  After this, NEVER touch the alignment of the reference mirror (motor 3). (Unless redoing 
  the internal alignment)

The system is now autocollimated out to the BRT.
We now need to align out to whichever sids we are using.
Autocollimate to the siderostats (External Autocollimation)
-Start up sidcons etc, start an autocollimation astromod (astromod -a in an 
 arthur window) and autocollimate the siderostats (ie. track).
-Remove the double-target from the BRT, slide the autocol mirrors out,
 and remove the lower periscope mirror covers (at east end of BRT table).
-Light should be reaching the sids and returning. With about 2.3+1.3+1.5 ND 
 (at 40m  and more for shorter baselines) in front of the laser, acquire the
 S beam with the acquisition system, ie. on stMsg
-The spot should move close to its (S) box on wobble2. Use 'adjust' on sidcongtk
 if not, and close the servo loop to centre up the spot.
-Switch off the red box on stMsg and set the origins in stMsg.
-Move the pellicle to N, wait till the 'Actual rates AZ/EL' in sidcon S are <2 or 
 so, then open the servo loop to let the sids stop.
-Repeat for N beam.
-If the spot had to move more than about 2cm on the stMsg display, then put 
 the autocolimation positions in the sidstats file. Write them down from the
 sidcon displays, then type 'susiedit sidstats' in an arthur window.
 (r,R-esc, shift zz, y, rtn, a, now add a comment[initials ?x?x-?], esc to exit vi, shift zz)
Align on a star
Should have:
 [srcin]   all shutters open
and enclosure ready to observe,
ie. lights off, laser off, air-con off maybe (on in summer, perhaps), sids stopped, etc

-Manually centre and zero the OPLC using PLC.
-Open the siderostat rooves if not already done.
-Switch on stMsg and turn up intensifier.
  Use ~4.5 for a R=2-3 star, 6 for R=3-4 star.
-Take darks in track,ref,widefield in wobble2gtk.
-Move to a bright (2nd mag or brighter) alignment star, preferably using
 the scheduler, ie. type in load ../schedules/starname.sched (or whatever
 you've called it) and click 'single command'. This will acquire the
 alignment star.
-Put wobblegtk into widefield mode.
-All going well stMSg will acquire the star on N and pull it onto the origin.
 If necessary manually pull it in on stMsg.
-It should now be visible in widefield on wobble2gtk.
 If necesary, in wobble-widefield, move star onto blue box with 
 sidcon 'adjust' (need to switch red box on stMsg off) or...
-If close enough close N servo to centre star on wobble2gtk. Open servo and 
 set origin on stMsg
-Hit track in wobble2gtk.
-Scheduler will move pellicle to S. Repeat for S beam.
-Hit reference
-Do nmsin and check there really is a image in the wobble reference box.
 mnmsout, smsin and check again.
 If there is no image in the ref box move that beam in using the PHP (may
 need to go to widefield if things are really out of alignment) and move the 
 beamsplitters, motors 1,2
-In wobble2 set reference time (rs) to get reference counts >200 (>100 may be OK?)
 ie. close n and s shutters in turn and check ref counts in wobble2 are > 200 
 (>100 may be OK?)
-In scheduler do single command again. This will start the align command and trim up 
 the n and s beams, and finish by opening nms & sms and taking refout. Check that CCD ref
 values are close to or oscillating about 0 as the beams are trimmed up.
-Type tasc in wobble2 to allow auto servo loop closure in track mode.

  [ Alternative, and old procedure before automatic 'align':
   If seeing is not good might need to check ref beam is in box on widefield
   view. If not move it in before going to ref view. Could progressively reduce
   rs as you get ref beam more centred - this keeps ref counts high enough but
   rs low enough.
  -Do smsin
  -Do 'ts n'
  -Watch the reference values in wobble2 and wait till they oscillate about 0
  -Now (important!) type 'ts off'
  -Repeat for S beam (ts s) but with nmsin
  -Do refout, nmsout, smsout 
   Alternative-alternative method:
  -Just close each shutter in turn and move motors 1,2 manually with the PHP ]

-Now to track
-Switch on APDs
-hit go in scheduler...and observe!

For a full alignment add this next step
Align laser with OPLC rails
 Two people are needed to do this efficiently and it may need to be iterated.
 -Put 5mm apertures in behind beamsplitters
 -Put small targets in west exit apertures of both catseyes.
  Check they are correctly orientated - writing at top.
 -Adjust WC's to centre N and S beams on targets
 -Put a rail-alignment tool on rail just south of carriage.
  Adjust it to centre spot on target.
 -Go to end of south tunnel. Place r-a tool at marked location 
  (~3m up the rails). Adjust WCN mirror to centre spot on r-a tool.
 -Remove r-a tool. Adjust N-P-3 mirror to recentre spot on target.
 -Repeat above few steps to align south beam with north tunnel rails.
 -Now adjust N-P-2 and S-P-2 mirrors to centre spots on double-target
  at BRT

The beams are now aligned with the rails.


Alternative A
 -Switch on monitor (above central pier). monin on opttab2
 -Turn room lights out. Put in ND 1.6+0.3 in laser beam.
  Remove small apertures. On opttab2 refout.
 -Switch on monitor camera (power below at foot of red table)
 -Cover south beam at central pier. Move north autocol mirror 
  to maximise illumination on monitor
 -Repeat for north beam/south mirror
 -With both beams open sould see fringes. "Fluff out" the fringes.
  ie. adjust a mirror slightly to remove them.
 -Switch off monitor and monitor camera.

Start up the siderostats, sidcons, sidcongtk's, etc. Do astromod -a (after astromod -k to kill any previously running a'mod) And track... Autocollimate to the siderostats (External Autocollimation) [Optional step to add here: aligning the outgoing laser on the vacuum pipe windows, or on the siderostats.] -Remove the double-target from the BRT and slide the autocol mirrors out. -Light should be reaching the sids and returning. Look for it near the beamsplitters, and progressively up the line if not found there. -If there is no return beam you'll need to go to the sids and find it. See other procedure (link to be here) for this. -If you have LDC blocks in south beam will see spurious extra images in wobbler widefield image. Will need to move the blocks out for this step to centre up S beam, and smsin to get N beam. Alternative 1 Using this method the absolute alignment of the beams is ensured (you can align the reference beam from this). -Take IBM latop to nearest live port (say 55 near BRT). Login as observer to arthur. -Start up sidcongtk nx & (where x is sid number) sidcongtk sx & -Open adjust windows [and status window]. -Adjust sid positions to bring the beam back to the beamsplitters. -monin, monitor on, monitor camera on. -Move the laptop near to the beamsplitters (port 51). Once again maximise the screen brightness for each beam then fluff out the fringes. May need to change the sid slew speed to 10 on sidcongtk. -monitor off, monitor camera off, monout Alternative 2 (easier, quicker) [coarse alignment] But with this method you are trusting that the origins of the acquisition system are accurate enough to put the beam on the wobble2 widefield view. You could also use this method to find a beam if it does not come back from the siderostat, but is still not too far out of alignment - just do a spiral search in stNG until the beam appears then grab and centre it. -Put ND 2.0+1.3 in. Should be tracking on sidcons -Now that beams are coming back into building can use startrackNG to centre them up as we should be able to see them on acquisition screen. (assumes origin coords on startrackNG are close to correct - usually true from night to night) -Start up startrackNG, go to N, should see laser spot -Acquire spot and centre. Appears on wobble widefield. -Move pellicle out of way (to S), Close N servo to centre in box then open servo. Check that the sids have stoped. -Repeat for S: acquire, centre, pellicle (to P), close, open, check. -Record sid autocol values here with 'susiedit sidstats' Aligning the north & south beamsplitters and ref beam [fine alignment] -refin, ND 2.0+0.3 into laser(or 2.0+1.3) -In wobble client do control|widefield. adjust bright/contrast. -Should see several images: n&s beams & n&s ref beams. -nmsin [If you used alternative 1 in the above step, then the next step should be moving the reference mirror, not the siderostat Moving the south siderostat will stop the 'doughnut' from being evenly illuminated.] -move S sid (control|move_siderostat) to get s ref beam in ref box -nmsout, smsin and move N sid to get ref beam in box Now have a reference beam aligned [very fine alignment] -nmsin and adjust, with PHP, south beamsplitter (motor driver 1) to get south beam into red square or close. -Close servo loop. Now to control|reference. adjust bright/cont -Now adjust beamsplitter again to get reference beam centered. ie. approx zero 'ccd ref' values in wobble2. open servo -Repeat last 3 steps for tIhe north beam and north ref beam -inpout, smsout, nmsout, wdsout, edsout, LDC blocks back in, laser off, observing apertures in, stop tracking on sids You now have an aligned system. At last! But the fun's not over yet. Oh no! We've got real stars to observe:) Align on a star Should have: inpout, refin, monout all shutters open, enclosure ready to observe. ie. lights off, laser off, air-con off, sids stopped, etc -OPLC: Switch OPLC to run Check in PLC or pathcomp that actual OPD is zero (zero-point drifts) If not, on PLC reset centre position. [PLC on ra: use local version (cd ~susi/src/plc/control/, local) do auto startup. Then in pathcomp (or PLC, is same) set rate servo 1 to 6: ie. From pathcomp main menu: 4 2 3 down-arrow to "RtServo1", type in 6 (or range 4-8), esc and back to tracking.] -In arthur do astromod -kd [HR#] nx sx [periscope] [choose some bright star, your first cal maybe] -xrun_merlin (arthur). Check OPD in merlin and set LDC. -Wait a few (~10) seconds. Track on sidcons & pathcomp -Acquire star on stNG N -If necesary, in wobble-widefield, move star onto green box with 'servo control' (need red box on stNG off) -Close N servo. Set origin on stNG. Move pellicle to S -To control|reference -In wobble2 set reference time (rs) to get reference counts >200 If seeing is not good might need to check ref beam is in box on widefield view. If not move it in before going to ref view. Then progressively reduce rs as you get ref beam more centred - this keeps ref counts high enough. -Use PHP to adjust N beamsplitter so 'CCD Ref' position oscillates about 0 -Auto trim N beam -Repeat last seven steps for S but nmsin (so only S ref beam is on ref square) -refout, nmsout, smsout, control|track Now start taking data. -msd (arthur) -set fringecon_client parameters: LUT [short: scan35f_256; long: scan140_1024] damping (0.5 to ~5 to start with), filter (in micron), sample time=0.2 process type=equalise ADP's -Switch APD's on -start scanning, get a scheduler going, and record data...

Andrew Jacob
Last modified: Wed May 5 05:26:35 EST 2004