Weather Monitoring

Weather is a significant issue for ATCA observations: Rain attenuates signal at higher frequencies and lightening causes interference at lower ones. Critically, storms have the potential to cause serious damage to the telescope, so observers are expected to be vigilant in their monitoring of the weather. There are a number of systems in place to help this, however, never underestimate the value of going outside and looking around. Observers can be quite unaware of weather changes outside the comforts of the control room.

The sensors for the site `Weather Station' are on the tower in the paddock between the Control Building and the Visitor's Centre. The data from here is downloaded to a computer in the screened room, which responds to XBONES weather request and writes the data to a web page. System software on XBONES monitors the windspeeds from the weather station, and if two consecutive readings are above 40km/h, CAOBS will issue a stow command.

There are a number of warnings to alert you to problems with this system

Assistance reports that the weather values have not changed

This may well be true (especially if it is a calm night) however, it is a warning that you should check for problems

You notice that (inextricably) the wind speed and direction (as displayed on winds) is not changing

As above, this may not be a problem, but is reason to check for problems.

Assistance reports that the weather task has died

Check that this is really true by typing: XBONES> ps -ef | grep weather and checking if the `weather' task is there. Monit will usually restart the task automatically if there are any problems. If necessary, the Monit webpage can be used to restart it -- see the DA.

The error counts on the ATCA Weather Station Web page indicate problems

This may well indicate a problem with the electronics. Consult local staff.

Weather Station PC Programs not running

To restart: Select CAWEATHR on the KVM switch in the screened room (using the `print screen' key) Login as observer (password in `Expert's Guide' Folder) Press the left arrow on the following screens in this order: HTTP server TCP WS Remote WS Weather Station

The `Weather Station' terminal in the control room has been replaced by a web page that displays the output from the weather station. See www.narrabri.atnf.csiro.au/astronomy/weather.html

There is another anemometer on the control building roof. This is fed into the PMON system, and if this wind speed is above 50km/h, the PMON rack will issue a stow command.

This system is basically independent of the `weather station', so acts as a backup in the case of `weather station' failure.

Lightning activity can be monitored with MoniCA, or the webpage

http://www.narrabri.atnf.csiro.au/astronomy/lightning.html.

We try to ensure that generators are running before storm fronts hit and astronomers are asked to help by keeping an eye out for storms: If in doubt, consult the Duty Astronomer. (See section 4.1.5 on page  for more information.)