chara:operating_procedures
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| Wind has the effect of degrading the seeing as well as kicking up dust. The wind effects are amplified in the tunnel between the OPLE building and the office building, so look for other places to gauge the wind conditions. The intersection of the road and the trail to the eastern telescopes is a good place to gauge conditions. To be on the safe side, we only observe under calm to light breeze conditions (gusts less than about 10 knots, or 15 kph). Windy conditions we try to avoid. If you can hear the gusts from your desk, whistling from the light pipe supports, or the chain banging, it is too windy to observe. Occasionally you will hear the wind rustling the tops of the tall trees, but it is calm at ground level. This is a symptom of chaotic wind conditions, and almost always happens during windy episodes (Santa Anas, onshore flows, etc.), during which you shouldn’t observe – the seeing will be bad anyway. Be cautious about opening if wind gusts are above 15-20 kph; winds this high are usually correlated with bad seeing and poor data quality. Telescopes and domes should be closed if the wind gusts get up to 30 kph. This will protect the optics from branches and debris that can be blown in from the surrounding trees. | Wind has the effect of degrading the seeing as well as kicking up dust. The wind effects are amplified in the tunnel between the OPLE building and the office building, so look for other places to gauge the wind conditions. The intersection of the road and the trail to the eastern telescopes is a good place to gauge conditions. To be on the safe side, we only observe under calm to light breeze conditions (gusts less than about 10 knots, or 15 kph). Windy conditions we try to avoid. If you can hear the gusts from your desk, whistling from the light pipe supports, or the chain banging, it is too windy to observe. Occasionally you will hear the wind rustling the tops of the tall trees, but it is calm at ground level. This is a symptom of chaotic wind conditions, and almost always happens during windy episodes (Santa Anas, onshore flows, etc.), during which you shouldn’t observe – the seeing will be bad anyway. Be cautious about opening if wind gusts are above 15-20 kph; winds this high are usually correlated with bad seeing and poor data quality. Telescopes and domes should be closed if the wind gusts get up to 30 kph. This will protect the optics from branches and debris that can be blown in from the surrounding trees. | ||
| - | 4.5 Snow | + | 4.5 Snow and cold weather |
| - | Because of the nature of the snow that falls on Mount Wilson, it is usually not a problem. If snow/wind conditions are such that drifting occurs, don’t open up. If there is still any snow stuck to the telescope dome itself, don’t open up. If there is snow still on the trees and branches procede with caution and make a visual assessment. Cold temperatures around freezing also can be problematic. | + | Because of the nature of the snow that falls on Mount Wilson, it is usually not a problem. If snow/wind conditions are such that drifting occurs, don’t open up. If there is still any snow stuck to the telescope dome itself, don’t open up. If there is snow still on the trees and branches procede with caution and make a visual assessment. |
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| + | Cold temperatures around freezing also can be problematic. Several components are not rated to operate at freezing temps. Do not open unless it is above freezing and keep an eye on the temps if they are still dropping. Otherwise, you are free to observe (assuming the humidity, dust, and wind conditions allow it). Here are limits for observing close to 0ºC. | ||
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| + | Temp_warning: | ||
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| + | Hard_limit: | ||
| 4.6 Essential Observing Links | 4.6 Essential Observing Links | ||
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| 5.4 Turn on the telescope power \\ \\ | 5.4 Turn on the telescope power \\ \\ | ||
| - | Make sure the telescopes being used are in their stow positions. For each telescope, the elevation should be at or near 90 degrees and [SPY1] should show the end ring of the telescope framing the top of the open dome. The azimuth positions for each telescope should be: S1, S2 82.0 - E1, E2 55.9 - W1, W2 99.3. Make sure there are no demand positions that are different from stow positions or the scopes may beging moving without being commanded. Hit STOW if any \\ | + | Make sure the telescopes being used are in their stow positions. For each telescope, the elevation should be at or near 90 degrees and [SPY1] should show the end ring of the telescope framing the top of the open dome. The azimuth positions for each telescope should be: S1, S2 82.0 - E1, E2 55.9 - W1, W2 99.3. Make sure there are no demand positions that are different from stow positions or the scopes may beging moving without being commanded. Hit STOW if any \\ |
| On the Power GUI, turn on the [Tel AZ] and [Tel EL] power for each of the active scopes (green means ON). \\ | On the Power GUI, turn on the [Tel AZ] and [Tel EL] power for each of the active scopes (green means ON). \\ | ||
| The new for 2016 stall detection function usually has each scope disabled each evening. They will need to be enabled before checking the dome servers or slewing. Make sure that the telescopes do not move away from their stow positions when enabling the scopes. If they begin moving, then click [STOW] on the Telescope Control Tab or dome gui and make sure that they arrive at the correct stow position. Check for problems with the dome servers by watching each telescope move to the precise stow position, ie. 89.990º and moving to 90.000º. If it stays off the precise stow position, the dome sever may need restarting. Click [REOPEN] on the dome gui if the clock is not the same as the CHARA time. | The new for 2016 stall detection function usually has each scope disabled each evening. They will need to be enabled before checking the dome servers or slewing. Make sure that the telescopes do not move away from their stow positions when enabling the scopes. If they begin moving, then click [STOW] on the Telescope Control Tab or dome gui and make sure that they arrive at the correct stow position. Check for problems with the dome servers by watching each telescope move to the precise stow position, ie. 89.990º and moving to 90.000º. If it stays off the precise stow position, the dome sever may need restarting. Click [REOPEN] on the dome gui if the clock is not the same as the CHARA time. | ||
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| If the flux is low on telescopes on pop 5 or 4, there can be a misalignment of the IR starlight with respect to the blue beacon due to low elevation and the long distance to the lab. If this is the case, follow these steps to improve the flux. | If the flux is low on telescopes on pop 5 or 4, there can be a misalignment of the IR starlight with respect to the blue beacon due to low elevation and the long distance to the lab. If this is the case, follow these steps to improve the flux. | ||
| - | On the obsgtk, set the beacon step size to 222 or 333. Click the Left button while watching the MIRCX flux plot or the STST image display. If watching the MIRCX flux plot, look for increases in flux after a click or two. Allow the DM AUTO function to adjust the blue beacon after each step by not moving the beacon out of the boxes. | + | On the obsgtk, set the beacon step size to 222 or 333. Click the Left button while watching the MIRCX flux plot or the STST image display. If watching the MIRCX flux plot, look for increases in flux after a click or two. Allow the DM AUTO function to adjust the blue beacon after each step by not moving the beacon out of the boxes. Remap the fiber to see if the flux is further increased when the labao has recentered the beacon. If using the STST, move the image flux towards the reference position set by the STS or CHARA beams. |
| 5.6 Locking Lab Tiptilt (only used in special cases) | 5.6 Locking Lab Tiptilt (only used in special cases) | ||
chara/operating_procedures.txt · Last modified: 2023/09/01 02:50 by gail_stargazer
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