Weather
| System: | weather.phys.utas.edu.au |
|---|---|
| IP address: | 131.217.63.161 |
| Processor: | Intel Pentium III 450 MHz |
| RAM: | 128MB |
| HDD: | 1 x 6.4GB IDE |
| Operating system: | Fedora Core 4 |
| Location: | Rear server room, under desk, Mt Pleasant observatory |
| Purpose: | Connected to MET3 weather sensor |
The observatory's MET3 weather sensor measures temperature, atmospheric pressure and humidity.
It is connected to this weather machine via serial port.
The computer runs the metserver code that is part of the PC field system station package, and
this is started on boot. This program is located at /usr2/st/metserver/metserver, and the code
is at /usr2/st/metserver/src.
This program starts up a network server listening on port 30384 for requests from clients. Almost continuously, the server will serially communicate with the sensor and get the latest weather data from it, and this data is stored in memory. Whenever a client connects to the server, the server passes the latest available data to the client.
A metclient task runs on hobart to log the weather conditions at the observatory. At boot
time for hobart, the program /usr2/st/metclient.old/metclient is started, and every minute
this process logs the weather conditions from the MET sensor to /usr2/log/wxYYDDDHO.log,
where YY is the last two digits of the year, and DDD is the day of the year. An example line
from this log is:
2008.334.04:57:48.00/wx/10.8,1002.3,69.7
The year and day of year are given at the start of the line, along with the UT time that the data
was obtained. The /wx/ refers to the task that got the data (because it is a field system task),
and the last three values on the line are comma separated; these are (in order) temperature (in
Celcius), atmospheric pressure (in HPa), and humidity (in %).
It should be noted that the old hobart machine had been logging this data since weather was
enabled in late 2006, but the new hobart only began logging data from 29 November 2008. It should
also be noted that the weather conditions presented on the live page do not come from the MET3 sensor.