|Processor:||Intel Pentium III 450 MHz|
|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
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.
metclient task runs on
hobart to log the weather conditions at the observatory. At boot
hobart, the program
/usr2/st/metclient.old/metclient is started, and every minute
this process logs the weather conditions from the MET sensor to
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:
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
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.