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chara:discussion_of_alignment_procedures [2024/07/10 19:09]
gail_stargazer 		chara:discussion_of_alignment_procedures [2024/07/10 19:35] (current)
gail_stargazer
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   * If coma and astigmatism high, create sky flat on bright star - Turn off **[DM]**, **[SV FLT]**, **[FLATEN]**, then relock the **[DM]**.   * If coma and astigmatism high, create sky flat on bright star - Turn off **[DM]**, **[SV FLT]**, **[FLATEN]**, then relock the **[DM]**.
   * For IR combiners, move beacon flat to align star to STST.   * For IR combiners, move beacon flat to align star to STST.
-  * For SPICA, move beacon flat to align star on SPICA FTT. <font inherit/inherit;;#16a085;;inherit>(denis: we validated the combined method BF+M7 on E1 on April 23 and it did excellent worj, permitting to use the Right/Left,Up/Down axes of the IPDET to put the star in the FTT boxes.)</font>* Star Acquired. +  * For SPICA, move beacon flat to align star on SPICA FTT. <font inherit/inherit;;#16a085;;inherit>(denis: we validated the combined method BF+M7 on E1 on April 23 and it did excellent worj, permitting to use the Right/Left,Up/Down axes of the IPDET to put the star in the FTT boxes.)</font>* 
-  * <font inherit/inherit;;#1abc9c;;inherit>(denis: when FTT is locked turn on the offload to keep the alignment during tracking =⇒ good for FTT and good for Alignment. This has been successfully implemented in April 2024)</font>* When slewing to the next star, DO NOT send M7 to default. If next star is bright, then align beacon flat to center star on STST/SPICA FTT. If star is faint, keep beacon flat fixed or align beacon flat to center red beacon in offset beacon boxes on TelWFS.+  * <font inherit/inherit;;#1abc9c;;inherit>(denis: when FTT is locked turn on the offload to keep the alignment during tracking =⇒ good for FTT and good for Alignment. This has been successfully implemented in April 2024)</font>* 
 +  * Star Acquired. 
 +  * When slewing to the next star, DO NOT send M7 to default. If next star is bright, then align beacon flat to center star on STST/SPICA FTT. If star is faint, keep beacon flat fixed or align beacon flat to center red beacon in offset beacon boxes on TelWFS.
  
 ==== Proposed Revisions to Current Alignment Sequence ==== ==== Proposed Revisions to Current Alignment Sequence ====
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 First night with AO running on all 6 telescopes (after W2 DM installation): [[http://www.astro.gsu.edu/~schaefer/chara/movies/ao_video.mp4|video clip]] First night with AO running on all 6 telescopes (after W2 DM installation): [[http://www.astro.gsu.edu/~schaefer/chara/movies/ao_video.mp4|video clip]]
  
-Notes from Gail:+**Notes from Gail:**
  
 We took a short video last night comparing the spots on the Six Telescope Star Tracker (J-band) with the AO on versus AO off. There's still more optimization to be done, but it was good to see the dramatic improvement in spot quality on all 6 telescopes with the AO systems locked. We took a short video last night comparing the spots on the Six Telescope Star Tracker (J-band) with the AO on versus AO off. There's still more optimization to be done, but it was good to see the dramatic improvement in spot quality on all 6 telescopes with the AO systems locked.
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 The video starts with AO on. Then the AO servo's are turned off on all scopes and the images blur out. Finally, the AO loops are turned on again with well-defined compact spots. The video starts with AO on. Then the AO servo's are turned off on all scopes and the images blur out. Finally, the AO loops are turned on again with well-defined compact spots.
  
-Notes from Denis:+**Notes from Denis:**
  
 I have posted some SPICA images recorded during the same engineering tests. They can be viewed on this link: I have posted some SPICA images recorded during the same engineering tests. They can be viewed on this link:
  
-https://cloud.oca.eu/index.php/s/kpGeDZXWt8pGwAN+[[https://cloud.oca.eu/index.php/s/kpGeDZXWt8pGwAN|https://cloud.oca.eu/index.php/s/kpGeDZXWt8pGwAN]]
  
 For all sequences, we have, from left to right, E1-W2-W1-S2-S1-E1. Images are 10ms exposure and the gifs are 'almost' real time sequence of 30s (but continuous loop). For all sequences, we have, from left to right, E1-W2-W1-S2-S1-E1. Images are 10ms exposure and the gifs are 'almost' real time sequence of 30s (but continuous loop).
  
-  04-56-44: initial situation after opening and standard alignment. Large residual static aberrations on W2W1 clearly. Flux on E's is much less than others. Flat on W1, W2 does not improve the situation. \\ +  * 04-56-44: initial situation after opening and standard alignment. Large residual static aberrations on W2W1 clearly. Flux on E's is much less than others. Flat on W1, W2 does not improve the situation. 
-  06-31-05: We did a stow, then M7 to default, and then dichroic alignment. Situation is better (but seeing may have evolved in the meantime). \\ +  * 06-31-05: We did a stow, then M7 to default, and then dichroic alignment. Situation is better (but seeing may have evolved in the meantime). 
-  07-15-03: BF/M7 alignment. The TopLeft-BottomRight elongation is related to the atmospheric refraction (zenithal distance ~40°). \\ +  * 07-15-03: BF/M7 alignment. The TopLeft-BottomRight elongation is related to the atmospheric refraction (zenithal distance ~40°). 
-  07-30-33: same record close loop \\ +  * 07-30-33: same record close loop 
-  07-34-41: record open loop+  * 07-34-41: record open loop
  
 From the last record, it can be seen that the seeing was really poor. The encircled energy computation goes from 3% (open loop) to 7-8% in close loop. We are still far from 25% as expected but the atmospheric refraction (not yet compensated) is also a limitation of course, as well as the seeing conditions. Many beams have residual static aberrations, probably due to LABAO issues, and E's are really presenting a low transmission. From the last record, it can be seen that the seeing was really poor. The encircled energy computation goes from 3% (open loop) to 7-8% in close loop. We are still far from 25% as expected but the atmospheric refraction (not yet compensated) is also a limitation of course, as well as the seeing conditions. Many beams have residual static aberrations, probably due to LABAO issues, and E's are really presenting a low transmission.
chara/discussion_of_alignment_procedures.1720652966.txt.gz · Last modified: 2024/07/10 19:09 by gail_stargazer

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