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#AO Alignment for LGS Mode (Assumes currently reasonably aligned for NGS mode)
#

E.L.Gates

Last Update 25 July 2002


0. Install 600nm dichroic instead of mirror in 2nd dichroic mount.
1. Change to LGS WFS if necessary (see procedure elsewhere)
2. Put in alignment laser (need to remove first turning mirror)
3. Start APD TT software 
   a) telnet lgs3 and login as lgs
   b) procs
   c) kill proc for configngs
   d) /h0/usr/lgs/configlgs<>>>/nil &
   e) logout
   f) turn off relays for NGS TT Drive and Offloading
   g) LickAO - AO Loops - LGS APD Tip/Tilt
4. Put TT mirror in E-Null position 
5. Align through all pinholes with alignment laser 
   Note: Need to add irises in front of APDs and in front of hole
	 to back side of AO bench.
6. Coarse align to IRCAL (hit target on IRCAL dark cover)
7. Measure where alignment laser lands in IRCAL field. The alignment laser
   is a large spot on IRCAL, so record center of spot as best you can. 
8. Put in red light point source.
9. Move FiberStage X and Y so that the red light point source is centered
   on the same spot as the alignment laser. Aligning within a few pixels 
   is sufficient.
10. Align into slow WFS.
   a) Take exposure with slow WFS.
   b) Move TT cube to adjust centering (or the small turning mirror in front
      of the slow WFS). 
      TTCube Y-axis: -counts moves spots right, +counts moves spots left
      TTCube X-axis: +counts moves spots up, - counts moves spots down
      typical moves are a few thousand to a few hundred
11. Align APD TT sensor.
    a) Turn off red light source.
    b) Turn on white light source and turn brightness all the way up.
    c) Connect fiber to white light source and connect other end of 
       fiber to APD fiber #1 (back propagation). 
    d) Put paper target on DM.
    e) Examine centering of back propagation on DM target.
    f) Do steps c-e with the other 3 fibers.
    g) Determine if majority of fibers have the same centering, if so,
       move the small beam splitter cube to get good centering for
       that set of fibers.  
    h) Use small knurled knobs to adjust centering for each APD fiber
       that doesn't have good centering is step g.
    i) Now that all four APD fibers are coaligned, check to see if back 
       propagation hits the face of the red point source fiber (or white light
       source pinhole if it is at the cassegrain focus).
    j) Steer APD TT stage so that light hits the red point source fiber.
    k) Recheck back propagation centering for each fiber. If they are all off,
       use small beam splitter cube to recenter.
    l) Repeate j-k until satisfied with alignment.
12. Check centering on slow WFS. If not properly centered, fix and repeat
    step 11.
13. Align into IRCAL (pointing and pupil alignment).(see procedure elsewhere)
14. Boresight WFS to IRCAL by fieldsteering (Fast WFS P&C Control)
    red light source on WFS. 
15. Boresight APDs to IRCAL.
    a) See if light hits APDs, if not, use mover to find it. If all else
       fails, go back to steps 11j-k. 
    b) Close TT loop.
    c) See where light hits IRCAL.
    c) Steer APD TT stage (using micrometers) so that red light source 
       (or white light, if that is the source you are using) is well 
       pointed on the WFS and hits right spot on IRCAL (should be the same
       if did step 14 correctly).
    d) Open TT loop.
16. Change software back to NGS mode.
    a) turn off APDs
    b) telnet lgs3 and login as lgs
    c) procs
    d) kill proc for configlgs
    e) /h0/usr/lgs/configngs<>>>/nil &
    f) logout
    g) turn on relays for NGS TT Drive and Offloading
    h) Dismiss LGS APD Tip/Tilt window.   
17. Focus IRCAL. (see procedure elsewhere)
18. Image Sharpen IRCAL. (see procedure elsewhere).

#
# Getting started with LGS mode on the sky (after NGS observing the first
# half of the evening).
#

1. Move telescope to zenith position (5degrees N or S of zenith - S of zenith
   prefered due to position on radar, laser launch telescope and better known
   flexure of the AO bench)
2. Check internal AO alignment
3. Change software to LGS mode (both AO and Telco software!)
4. Turn on APDs
5. mover until find RLS. Jot down mover position for reference.
6. close TT 
7. Take exposure on IRCAL to be sure in right place. If not in right place
   open TT, put mirror in E-Null and see where you are. If still off in 
   alignment, move fiber stage. If correct, close TT and field steer APDs
   to put source in right place. 
8. Field steer WFS until pattern properly pointed and centered.
9. Call all motor positions for dichroics, TT cube and WFSM zero.
10. Put in WLS
11. Check internal Strehl.
12. Change to LGS control matrix, refcents and hartmannModes
13. Make sure radar on and visual observers ready.
14. Propagate laser.
15. Record NGS telescope focus.
16. Focus telescope on laser guide star
17. Record LGS telescope focus.
18. Focus laser spot using laser launch telescope optics.
19. Take slic video picture of laser guide star 
    (for reference/archive purposes)
20. Have laser operator steer spot to boresight position on guide tv.
21. Have laser operator steer spot to center of WFS (WFS still at NGS focus)
22. Close iris to 0 or 1000 counts.
23. Tune laser off wavelength, take cflat on WFS
24. Tune back on wavelength
25. Close uplink TT. 
26. Close AO.
27. Open loops and shutter laser.
28. Move telescope to 8 or 9 magnitude SAO star near first science target.
29. Refocus telescope.
30. Close loops and check strehl on star (NGS WFS position, APD TT).
31. Tune APD TT gain
32. Take reference BWFS image.
33. Mover to where APD TT wants mirror to be after offloading.
34. Open loops, mark boresight position on guide tv (bin x1), and 
    record boresight pixel position using Slic.
35. Move WFS back to LGS focus.
35. Propagate laser and boresight
36. Move iris to clip Rayleigh, if necessary. 
37. Take new cflat, if necessary.
38. Field steer TT star off axis (so not on WFS).
39. Close all loops and check strehl. Tune gains. 
40. Use BWFS to adjust position focus position of WFS.
41. Open loops. 
42. Field steer APDs to science target tip-tilt star off axis position.
43. Move telescope to tip-tilt star and position on proper pixel using Slic.
44. Close APD TT.
45. Propagate laser.
46. Close loops.
47. Take science data.
48. Adjust WFS focus position periodically to adjust for zenith angle/airmass.


#
# Going back to NGS mode after LGS observing 
#

1. Switch back to NGS mode software.
2. Load in NGS centroids, control matrix and hartmannModes. 
2. Move WFS to NGS focus.
3. Close loops on white light source.
4. Focus spot on IRCAL by moving WFSFocus stage (not IRCamFocus!)
   (either do a regular focus fit run or use BWFS - 1st choice seems to 
   be more accurate)
5. Go to science target guide star and observe!

#
#Afternoon LGS Alignment Check
#

1) exit ircalui, move data (using ircalcopy script) and restart ircalui
2) turn on TT and DM and 24V motor power
3) start APD TT software, turn off T/T Drive
4) put mirror in E-Null
5) see where rls hits ircal
6) if rls is not at (or near) center of ircal, first check ircal 
steering mirror micrometers
to make sure one of them hasn't been bumped, then move FiberStage X&Y to 
correctly position rls
7) close APD TT on rls or wls 
8) see where hits ircal
9) APD P&C to get source to hit same spot on IRCAL with TT closed as in E-Null
10) Steer WFS P&C until well aligned (WFS Tip and Tilt readings 
very small, e.g. +-0.05) with APD TT closed.
11) Call the positions of all the field steer motors zero.
12) Close AO loop and check WFS position with BWFS, if far from NGS focus 
position. You can skip this step if you are reasonably close to NGS focus.
13) Switch back to NGS TT mode:  start configngs on lgs3, turn on T/T Drive,
push NGS button in the Powerup checklist.
14) close loops and check strehl on IRCAL with wls
15) fine focus IRCAL (typically move WFS since that has been moved between 
    NGS and LGS focus)
16) Image sharpen on IRCAL