Rule 1: In bad weather, close the Robodome before shutting
down the software.
This is the quickest way to protect RoboDIMM from humidity or precipitation.
The software takes longer to
shut down and there are no serious consequences from having RoboDIMM
running inside a closed dome.
However, as soon as you can, shut down the software using "stoprobot".
Rule 2: Close the Robo-dome when there is RH>75% at any
of the ING telescopes.
Marco's statistics show that if humidity reaches 75%, it is most likely
to soon rise to >90% (correct me if I'm wrong, Marco).
At present there is no %RH measurement at RoboDIMM, so this policy
is the best way to ensure that the equipment is not exposed to
high humidity. Another advantage of this policy is that Robodome will
already be safely closed when it comes
time to decide whether to close the WHT dome.
Snow and/or Ice
Rule 3: If you are at the telescopes when snowy or icy weather begins,
day or night, please follow the same procedure
as detailed for "Lightning" below.
Following ice or heavy snowfall, it may become impossible to open the Robodome
for several days. Therefore, as soon as this
kind of weather appears, RoboDIMM needs to be prepared for a long term
shutdown. It is preferable to individually power down
delicate items of RoboDIMM hardware, in case there is an electrical
storm during this time. However, we recomment leaving the dehumidifier
switched on because this keeps %RH inside the Robodome below 75%.
In conditions of high humidity, low temperatures and wind, ice coverage
can become quite severe, covering not only the dome opening
but also encasing the dome motors in ice. After such an episode, the
ice should be allowed to fully melt before attempting to open the Robodome.
Someone must inspect it during daytime, preferably RoboDIMM Project Manager,
Carlos Martin. It must never be assumed that the Robo-dome is free of ice
just because it becomes safe to open the WHT dome, following an ice episode.
The telescope shakes a lot even in moderate wind, resulting in the star
image not appearing completely inside
the CCD sub-window during a seeing measurement series. This is
easily observed on the new GUI display.
Besides making it (near) impossible to measure seeing, this amount
of movement may be damaging to the
telescope drive mechanisms.
Therefore we recommend closing the RoboDOME if Wind speed or Gust read
35 kph on either the WHT or
JKT mast readings. You may also close if you observe so
much image motion that seeing is not being
Carlos is currently working on improving the isolation of vibrations
in the central "Serrurier" tower, coming from
the access platform, by changing the humidity-sealant material between
Rule 4: If the WHT has to stop observing because of cloud, definitely
close the Robodome. It is much more important
to protect RoboDIMM from rain than to take data through cloud. Note
that RoboDIMM may have no problems
observing even when cloud is too thick for the observing program at
We plan to install a rain alarm next spring.
Rule 5: if an electrical storm is observed anywhere in the sky,
even if this is currently on the horizon and the WHT
can still observe (as can happen), we recommend that delicate systems
powered down, using the procedure
Electrical storms are particularly dangerous because RoboDIMM is a possible
lightning conductor. The cables
that link it to the WHT building have lightning protection built in,
but RoboDIMM itself is still vulnerable. Since such storms are
usually accompanied or shortly followed by wet weather, RoboDIMM should
in fact be prepared for a long term shutdown.
This procedure is designed to safely shut down the RoboDIMM hardware
prior to a possible decision
to shut off RoboDIMM power at source, to be taken by the Incident Officer.
Procedure for long term shutdown:
Close the Robodome and shut down the software in the usual way.
Shut down the Robo-PC by entering at the user (root) prompt the command:
> shutdown -h (This securely closes
down linux and powers the PC off).
Now go inside the RoboDIMM tower and remove the plugs from their sockets
for the following devices:
PC, telescope power supply, CCD power supply, network hub for PC, lamp.
Switch on the dehumidifier, turn it up fully, make sure the exit hose is
connected: locate its exit at the edge of a damper panel,
where there is a tiny gap.