chara:operating_procedures
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chara:operating_procedures [2023/07/27 17:08] gail_stargazer |
chara:operating_procedures [2023/09/01 02:50] (current) gail_stargazer |
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| - | ===== Observing Procedures ===== | + | ====== Observing Procedures |
| - | [[:chara:New Operating Procedures|New Operating Procedures Page - Under Construction]] | + | [[:chara:new_operating_procedures|Link for New Operating Procedures Page - Under Construction]] |
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| {{https:// | {{https:// | ||
| - | When the laser is on, the circle marked Laser will be green and the wattage listed will be close to 80mw (instead of 20mW when off) | + | When the laser is on, the circle marked Laser will be green and the wattage listed will be 65-80mw (instead of ~20mW when off) |
| All the circle indicators start out grey. | All the circle indicators start out grey. | ||
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| There are six computer screens which are now horizontally arrayed. Window layouts can be saved and reloaded to suit each operator. Use the third icon from the left in the toolbar (Operator Layout) to open a window to save or load a layout. After a restart on zoot, the necessary windows to observe can be brought up using the fourth icon from the left in the toolbar (Observation Setup). | There are six computer screens which are now horizontally arrayed. Window layouts can be saved and reloaded to suit each operator. Use the third icon from the left in the toolbar (Operator Layout) to open a window to save or load a layout. After a restart on zoot, the necessary windows to observe can be brought up using the fourth icon from the left in the toolbar (Observation Setup). | ||
| - | 3.2 Setting up for observin | + | 3.2 Setting up for observing |
| Start the OPLE server. Let the MIRCX and MYSTIC observers know it is running. Some will start the STS data recording before Ople is started, but others may want it running. | Start the OPLE server. Let the MIRCX and MYSTIC observers know it is running. Some will start the STS data recording before Ople is started, but others may want it running. | ||
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| In the WFS tab of the telescope GUI or the CONTROL tab of the obsgtk, turn on the red LED, open the fiber covers, then beacon flat covers. The CAMERALINK and WFS server are now part of Bootlaunch script and the ANDOR camera power should always be on in the POWER gui. Open M5 and M7 covers. | In the WFS tab of the telescope GUI or the CONTROL tab of the obsgtk, turn on the red LED, open the fiber covers, then beacon flat covers. The CAMERALINK and WFS server are now part of Bootlaunch script and the ANDOR camera power should always be on in the POWER gui. Open M5 and M7 covers. | ||
| - | The blue beacon is no longer an LED and has been replaced by a tunable laser. | + | The blue beacon is no longer an LED and has been replaced by a tunable laser with its own gui. |
| Start the control GUI for the blue beacons from a terminal on any CHARA computer by typing tunable_beacon | Start the control GUI for the blue beacons from a terminal on any CHARA computer by typing tunable_beacon | ||
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| **NOTE: | **NOTE: | ||
| - | Turn on the ACQ camera in the obsgtk. Make sure that the beacon is going through the hole in the acquisition display. If not, use Beacon UP/DOWN etc buttons on a HUT gui or WFS tab on the obsgtk to move it into the hole. Look for spots to be in boxes on the WFS display. Turn on the boxes on the obsgtk [BOXES] to see how the alignment is. The boxes may be in the default position or may be moved to a position that worked better when observing. | + | Turn on the ACQ camera in the obsgtk. Make sure that the beacon is going through the hole in the acquisition display. If not, use Beacon UP/DOWN etc buttons on a HUT gui or WFS tab on the obsgtk to move it into the hole. Look for spots to be in boxes on the WFS display. Turn on the boxes on the obsgtk [BOXES] to see how the alignment is. The boxes may be in the default position or may be moved to a position that worked better when observing. |
| - | Turn labao camera [ON] and [START] the display. Make a dark with the [MKDRK] button in the LABAO section of the obsgtk. Turn on the blue beacon. The blue beacon should show spots on the LABAO display. Adjust the FPS lower if they are dim. 100 FPS is the default, but 40 is often used for observing. **Set the M7 mirror to the default position.** | + | Turn labao camera [ON] and [START] the display. Make a dark with the [MKDRK] button in the LABAO section of the obsgtk. Turn on the blue beacon. The blue beacon should show spots on the LABAO display. Adjust the FPS lower if they are dim. 100 FPS is the default, but 40 is often used for observing. **Set the M7 mirror to the default position.** |
| - | If the spots do not show at all in the labao, the scope dichroic is likely out of alignment. Turn on the lab laser and set it to ND 4.0. Look for additional spots in the ACQ window that are not from the beacon. Use the Dichroic controls to make the laser spots match the blue beacon spots on the ACQ camera view. Up is to the upper right in the ACQ view. If they are way off or not visible in the ACQ, you can hit the button for the appropriate dichroic in the HUT gui and it will set the dichroic to its last saved default position. | + | If the spots do not show at all in the labao, the scope dichroic is likely out of alignment. Turn on the lab laser and set it to ND 4.0. Look for additional spots in the ACQ window that are not from the beacon. Use the Dichroic controls to make the laser spots match the blue beacon spots on the ACQ camera view. Use large steps such as 2500 to bring the spots together. Up is to the upper right in the ACQ view at STOW. If they are way off or not visible in the ACQ, you can hit the button for the appropriate dichroic in the HUT gui and it will set the dichroic to its last saved default position. |
| Note the focus term on both the TWFS and LABAO GUIs or obsgtks. The next steps will minimize both focus terms. Start with the (BEACON FOC) button on the ALIGN tab of the LABAO GUI or [FOCUS] in LABAO: section on obsgtk, wait until the procedure finishes. Then use the (FOCUS WFS) button on the ALIGN tab of the TWFS GUI or [FOCUS] in middle section on the obsgtk and wait for completion. Note that focusing the beacons does not work when the spots are not reasonably centered. Always get the spots well into the boxes first before focusing. Sometimes it helps to repeat the scope dichroic alignment and focus as each needs the other to be close to align well and large changes in the labao focus can put the TWFS out of alignment also. As the scopes are cooling, these alignments will drift and will need to be done before slewing to the first target. | Note the focus term on both the TWFS and LABAO GUIs or obsgtks. The next steps will minimize both focus terms. Start with the (BEACON FOC) button on the ALIGN tab of the LABAO GUI or [FOCUS] in LABAO: section on obsgtk, wait until the procedure finishes. Then use the (FOCUS WFS) button on the ALIGN tab of the TWFS GUI or [FOCUS] in middle section on the obsgtk and wait for completion. Note that focusing the beacons does not work when the spots are not reasonably centered. Always get the spots well into the boxes first before focusing. Sometimes it helps to repeat the scope dichroic alignment and focus as each needs the other to be close to align well and large changes in the labao focus can put the TWFS out of alignment also. As the scopes are cooling, these alignments will drift and will need to be done before slewing to the first target. | ||
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| 4.2 Humidity | 4.2 Humidity | ||
| - | Only open the telescopes if the humidity is steady or dropping, at 75% or below. If the roofs outside the control room are ever dripping, then the telescopes should not be opened or should be closed immediately. If when starting out, the RH is above 80%, do not open unless it drops to below 75% and stays there for at least 30 minutes. Be aware that if the RH is at 100% for many hours, things will be very wet, even if the RH drops dramatically below 75%. If you do open after that, be wary and watch the RH, and if it starts rising, be prepared to close. Closing up takes about 5 minutes, so be ready for that. The array operator is in charge of protecting the telescopes and makes the final decision on whether the conditions are safe to open. If the RH is low at the beginning of the night, and rises after you are already open, the array operator should inform the PI around 70-75%, and start closing between 80-85%. Other humidity warning signs are: 1) water dripping off the OPLE building (or wet spots on the asphalt straight down from the eaves); 2) cold, clammy feel to metal objects such as railings; and 3) dew forming on the parked cars. It is important to note that the humidity can rise from 50% to 80% in as little as 10 minutes, so please keep a close eye on the rate of change of the humidity plots. It can also rain or hail from small, passing clouds when the humidity is quite low, even 40% RH or lower. Operators have been surprised before by small puffy clouds in unsettled air with low humidity. If in doubt, stay closed. The HPWREN webcams are a good resource to view the bottoms of clouds. If there is any virga, the clouds are holding moisture and try to rain out. Stay closed if you see anything streaming below the clouds. | + | Only open the telescopes if the humidity is steady or dropping, at 75% or below. If the roofs outside the control room are ever dripping, then the telescopes should not be opened or should be closed immediately. If when starting out, the RH is above 80%, do not open unless it drops to below 75% and stays there for at least 30 minutes. Be aware that if the RH is at 100% for many hours, things will be very wet, even if the RH drops dramatically below 75%. If you do open after that, be wary and watch the RH, and if it starts rising, be prepared to close. Closing up takes about 5 minutes, so be ready for that. The array operator is in charge of protecting the telescopes and makes the final decision on whether the conditions are safe to open. If the RH is low at the beginning of the night, and rises after you are already open, the array operator should inform the PI around 70-75%, and start closing between 80-85%. |
| + | |||
| + | Other humidity warning signs are: 1) water dripping off the OPLE building (or wet spots on the asphalt straight down from the eaves); 2) cold, clammy feel to metal objects such as railings; and 3) dew forming on the parked cars. It is important to note that the humidity can rise from 50% to 80% in as little as 10 minutes, so please keep a close eye on the rate of change of the humidity plots. It can also rain or hail from small, passing clouds when the humidity is quite low, even 40% RH or lower. Operators have been surprised before by small puffy clouds in unsettled air with low humidity. If in doubt, stay closed. The HPWREN webcams are a good resource to view the bottoms of clouds. If there is any virga, the clouds are holding moisture and try to rain out. Stay closed if you see anything streaming below the clouds. | ||
| 4.3 Dust | 4.3 Dust | ||
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| 4.4 Wind | 4.4 Wind | ||
| + | |||
| + | **Use caution if wind gusts > 15-20 kph** | ||
| + | |||
| + | **Close up if wind gusts > 30 kph** | ||
| 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. | ||
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| 4.5 Snow and cold weather | 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. | + | 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. 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. | + | 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 freezing: |
| - | Temp_warning: T_tel <= 2C or T_outside <= -3C | + | **Temperature warning: T_tel < 2C or T_outside < -3C** |
| - | Hard_limit: T_tel <= 0C or T_outside <= -5C | + | **Hard limit for closing: T_tel < 0C or T_outside < -5C** |
| 4.6 Essential Observing Links | 4.6 Essential Observing Links | ||
chara/operating_procedures.1690492136.txt.gz · Last modified: 2023/07/27 17:08 by gail_stargazer
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