Last Update: 23rd December 2020
For Users of the Nobeyama 45-m Telescope Open Use Program
The basic observing mode is a remote operation.
Nobeyama Radio Observatory (NRO) offers the observation support by observatory staff remotely from the Nobeyama site.
Rules about the assistant are as follows:
- The NRO assistant will support only during the staff business hours of 9:00-17:00 JST, Monday through Friday (including national holidays).
- NRO recommends that observers learn basic operations with technical support from the NRO assistant so that they can conduct observations by themselves.
- To promote smooth open-use observations, the NRO assistant will help the observer to operate the Nobeyama 45-m telescope and coop with instrumental troubles as necessary.
- The scope of the support will be determined according to the skill and experience of the observer through discussions between the observer and the NRO assistant.
- The NRO assistant does not assist in creating observation scripts and reduce data.
If necessary, please request a support astronomer from the Helpdesk.
- The assistant on duty may have a one-hour break during observation with the consent of the observers. We appreciate your understanding.
- The communication between the observer and the assistant is expected to be done on #ObsMessages at Rocket.Chat in English.
For the weather and instrumental reasons, the observatory demands a suspension of the operation.
If the observer encounters these situations, please stop the observation and follow the instruction.
For each case, make sure that
- the telescope is parked as the instructed position (if not specified, please park at the zenith position [the elevation angle of 90 degrees])
- the message of the suspension of the operation and its reason is posted on #ObsMessages channel at Rocket.Chat
the "LOCK" button on the top left corner of the Nobeyama 45m Radio Telescope Console (shown in the NRO_RemoteObs_3 viewer) is pressed
(The antenna lock can be recovered if you press the "Release" button on the window)
The observer can leave the remote site after these three procedures above are properly executed.
The following rules are the criteria and the instructions for the suspension of the operation:
When maximum wind speed exceeds 20 m s-1 or greater, stop the observation immediately and park the telescope at zenith (EL=90 degree) position.
In case of strong wind, the window of Weather Alert (strong wind), appears on the COSMOS console, which is shown at the NRO_RomoteObs_1 viewer.
The operation must suspend until 30 minutes have passed after the wind whose speed was faster than 20 m s-1 blew.
Recent 30 minutes wind speed can be checked at Wind speed 30 min in the NRO Weather Condition page.
When it snows at daytime, the observer must stop observations immediately based on the assistant's judgment
because the Snow Monitor is not operated during the daytime due to the influence of sunlight.
Park the antenna at the azimuth angle so that the telescope faces the lee side of the wind (i.e., the angle of "wind direction" ± 180 degree) and the elevation angle of 11 degree.
Note that the drivable range of the Nobeyama 45-m telescope in the azimuthal direction is from -87 to 447 degrees.
If it snows at night, the observer must stop the observation immediately, and park the antenna in a safe position. The snowfall can be judged at the 45m Snow Monitor(can only be accessed via NRO VPN or inside NAOJ). In case of snow, the window of Weather Alert appears on the COSMOS console, which is shown at the NRO_RomoteObs_1 viewer. Do not operate the telescope until 9:00 JST the next morning.
If snowfall is found at night, the observer should leave a comment that you will not observe due to snow on #ObsMessages? channel at Rocket.Chat.
If the wind speed frequently exceeds 20 m s-1 with snow, please park the telescope at the position that the azimuthal angle = "wind direction" ± 90 degree and the elevation angle of 11 degree.
The assistant will announce to resume the operation on #ObsMessages channel at Rocket.Chat after the observatory staff check whether the snow on the surface of the antenna is melt.
High Risk of a Frozen Gear
If the anemometer freezes in dense fog and below freezing point (i.e., the wind direction is not changed although the wind speed indicates faster than 0-1 m s-1), the gear of the telescope is in a risk of frozen.
In that case, the observer shall stop the operation and leave the elevation angle unchanged.
Rise of Temperature of FOREST Receiver
When dewar temperature of FOREST receiver on FOREST monitor (in the NRO_RemoteObs_4 viewer) exceeds 6K, the performance of the receiver will decrease significantly.
The observer who does not use the FOREST receiver can continue the observation.
However, if you notice the situation, please report it on #trouble_report channel at Rocket.Chat
In the case of observation at 100 GHz and higher frequency, no good results can be expected under the following conditions:
Under such situations, the observer can give up the observation (, although the observing time may not be compensated).
- Maximum wind velocity: 10 m s-1 or greater
- System noise temperature: 1000 K or higher
- When the observer feels the earthquake during the observation, all he/she has to do first is to protect one's body.
- If the observer noticed that an earthquake struck the Nobeyama site, stop the observation after ensuring one's safety and check the Nobeyama 45m Radio Telescope Console (shown in the viewer of NRO_RemoteObs_3).
- When a big earthquake struck Nobeyama, the Director of the Observatory explicitly declares to stop the operation on #ObsMessages channel at Rocket.Chat
- In case that the earthquake struck in the daytime when the assistant is allocated, please follow the steps below:
- The assistant checks the states of the azimuthal rail, the lower cabin, and the elevation gears.
- The antenna is found to be in safety, check the pointing accuracy.
- If the antenna pointing is significantly different (> 20 arcsec.) in comparison with that before the earthquake, no further observation is allowed.
(The observatory will examine the whole system.)
- The observer resumes the observations if the pointing accuracy has no problem.
In the night when there is no assistant, the process is changed based on the level of the earthquake on the Japanese earthquake scale.
- the level of the earthquake > 4 level
Stop the telescope in that state.
Report the situation on #ObsMessages channel at Rocket.Chat
- the level of the earthquake ≤ 4 level
Check the pointing accuracy.
Even if the level of the earthquake ≤ 4 level, stop observation immediately in case that the pointing accuracy is significantly worse (> 20 arcsec.) before the earthquake.
Report the situation on #ObsMessages channel at Rocket.Chat.
The decision to resume will be made at 9:00 JST when the next assistant will come.
The observatory may suspend observations for other reasons.
If there is no next observer at the end of observations, set the antenna at zenith (EL = 90 degrees) position. However, if snowfall is predicted for even one hour in the weather forecast between the end of the observation and the next observation, the observers must park the antenna at the azimuth angle (Az) of 180 degrees (south) and the elevation angle (El) of 11 degrees.
The last observers on Saturday morning (or Friday night) must park the antenna at Az = 180 degrees (south) and El = 11 degrees after the observations are finished.
The time slots that are not explicitly allocated between observations (white-coloured slots on the schedule) are basically used for measurements or test observations by the observatory.
If no measurement or test observation is planed, the assistant will announce the situation on #ObsMessages at Rocket.Chat (Note that no announcement may be made for the night-time).
In this case, you can share and make use of the extra time after mutual consultation with relevant observers whose observation slot is allocated on before or after that time.
Before starting the observation, please declare it on #ObsMessages at Rocket.Chat as the observing time officially allocated.