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Last Update: 15th Januray 2017

A Flowchart for the Observations with the 45-m Telescope

This flowchart illustrates the processes of the observations with the 45-m telescope. Successful observations follow the left side of the flow. An assistant helps you to do processes coloured in orange. What your assistant can do for you is summarised in Rules for the Assistant. In order to shorten communication time between users and the assistant, the observatory encourages experienced users to change the mirrors and tune the receiver by themselves. For some procedures, detailed information is described in links. Special instructions for remote observations from NAOJ Headquarter in Mitaka, Tokyo can be found at the observing room in Mitaka.

Before Your Observations There is snow
Check the weather. right arrow In case of snow, you can not observe even if there is a little snow on a surface of the antenna. You may tell the assistant in the observing building by extension line (ext. 4341) that you can not observe due to snow and do not need to go to the building.
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It is not Snowing There is Strong Wind or It Rains Heavily
Go to the observing building before your observing time. All observing time is separated with Local Sidereal Time (LST). LST Clock may be useful to know the LST at the observatory. A conversion tool from Japan Standard Time (JST) to LST is provided at JST-LST Table (NRO). Sometimes no observations are allocated a few hours before/after your observations. In such a situation, you may perform your observation after negotiation with relevant observers who have a time before/after your observations. Since observations may be added for compensation observations and internal use, you should check the recent schedule displayed at the observing building before observations. If there is too strong wind or heavy rain not to observe your observations, you can give up observations and concede your observing time to the backup program which can be performed under bad weather if they are allocated at same LST range (please tell the assistant your will). In case backup observations are performed during allocated observing time, your observing time will be compensated later. You can check whether backup program is allocated within your observing time at the observing room. Weather criterion is described at Rules for Bad Weather page.
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Taking Over the Priority of the 45-m telescope
When the LST from which your observations start comes, you take over the priority of the telescope from previous observer. First of all, you fill observing ID and project name in COSMOS, the observing system of the 45-m telescope.
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Changing the Direction of Mirrors
Since the 45-m telescope has multiple receivers, users should change the mirrors in order to ensure a light path to the receiver which you will use.
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Receiver Tuning
For T70 receiver, choose an observing table of the main target which you want to observe on that day and press the button "TUNING" on COSMOS (You don't need this process when you use the FOREST, H22, H40, and Z45 receiver). When you plan to request the assistant to tune the receivers, it is helpful to print out the device table of the main target. Details on the receiver tuning are different with each receiver. Follow the receiver tuning instruction page.
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Observations with the 45-m telescope consist of 3 parts:
  1. Main Observations:
    Observations of your target(s).
  2. Pointing Observations:
    Observations of a pointing source in order to check and correct the pointing accuracy of the telescope. Generally saying, you need to perform pointing observations once per 1~1.5 hours (it depends on weather conditions).
  3. Standard Source Observations:
    The observatory recommends to perform observations of a standard source in order to calibrate the daily variation of the system. Standard source observations should be done once per a day. If the target line intensity of the standard source is too weak (< a few Kelvin), you can calibrate the daily variation with measuring the image rejection ratio for a 2SB receiver at the receiver tuning process, instead.
If you use different receivers between main observations and pointing observations (typically, H40 receiver), you need to change mirrors when switching between the two.
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During Observations Trouble Shooting
You should check some monitors and weather during your observations. The COSMOS terminal presents current status of your observations according to your observing script. Quick Look monitor shows the spectra. Weather monitor and this page can help you to dicide frequency of pointing observations and whether you handover your observing time to backup programs. right arrow In case that observations stop with red message on the COSMOS terminal and a crack of breaking glass, there should be trouble(s) on the execution of observations. The first way to do is to check the error message. The assistant may know the action on error. Please follow his/her instruction. Note that if the trouble happened with your observing script which has not used ever, please check your script whether it may be due to your script.
End of Observations
You MUST quit observation BEFORE the end of your allocated observation time. The log of your observations can be found at log monitor. There are observation log and pointing log. These log of your observations can be printed out or be sent through e-mail.