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vatt:dome_flats [2020/12/21 18:49] paul |
vatt:dome_flats [2022/05/07 04:52] (current) paul |
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====== LED Dome Flats ====== | ====== LED Dome Flats ====== | ||
===== P. Gabor (standing on the shoulders of R. Boyle, E. Green and others) ===== | ===== P. Gabor (standing on the shoulders of R. Boyle, E. Green and others) ===== | ||
- | === Dec 21, 2020 === | + | === Dec 21, 2020, minor update Feb 13, 2022 === |
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* Suppose you want to obtain dome flats after observing. You will need to close the dome shutters, which should only be done with the mirror cover on. Therefore, stow the telescope, disable drives, close mirror cover, and close dome shutters. Then, open mirror cover, and enable drives. | * Suppose you want to obtain dome flats after observing. You will need to close the dome shutters, which should only be done with the mirror cover on. Therefore, stow the telescope, disable drives, close mirror cover, and close dome shutters. Then, open mirror cover, and enable drives. | ||
* The telescope is still in the stowed position, i.e., nominally at Az=180°. With Dome tracking enabled, right click on the Dome azimuth field in TCSglue and introduce an offset of +190°. Wait until the dome stops rotating to its offset position, bringing the screen to the South meridian. | * The telescope is still in the stowed position, i.e., nominally at Az=180°. With Dome tracking enabled, right click on the Dome azimuth field in TCSglue and introduce an offset of +190°. Wait until the dome stops rotating to its offset position, bringing the screen to the South meridian. | ||
- | * Slew to RA = LST + 2' | + | * Slew to RA = LST + 2' |
+ | |||
+ | ---- | ||
+ | |||
+ | * Go to the basement and turn off the oil system for the hydrostatic azimuth bearing. This can be done before, during or after the flats; in any case, **before you apply your muscles to the telescope** (see below). | ||
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* After finishing your flats, return dome to home Az=180°: Turn on Dome Tracking, right click on the Dome azimuth field, and eliminate the dome tracking offset. Keep Dome tracking on (you will need it later when you go to the dome). | * After finishing your flats, return dome to home Az=180°: Turn on Dome Tracking, right click on the Dome azimuth field, and eliminate the dome tracking offset. Keep Dome tracking on (you will need it later when you go to the dome). | ||
- | * Go to the basement and turn off the oil system for the hydrostatic azimuth bearing. | + | * Release |
- | * Return to the Control room and release | + | * Solo observers may have to prevent the telescope from slumping towards the horizon, using the small '' |
* In the dome, power up the stow pin system. Then move the telescope manually to the stow position, and insert the stow pins. | * In the dome, power up the stow pin system. Then move the telescope manually to the stow position, and insert the stow pins. | ||
* Use your presence in the dome also to home the dome position in the usual manner (manually tweaking the dome's encoder wheel). | * Use your presence in the dome also to home the dome position in the usual manner (manually tweaking the dome's encoder wheel). |