In the wider area of Athens (687 km2), 11 fully automatic telemetric hydrometeorological stations are installed and already operating in the framework of the METEONET network. This network was developed by the Centre for Hydrology and Informatics (CHI) of the National Technical University of Athens. The following table depicts the beginning of each station's operation as well as the sitting characteristics.
|Altitude||Coordinates (GGSR '87)|
The selection of the sites was based on the following criteria:
According to the WMO guidelines, for the monitoring of weather events in a local scale (e.g. storms), the sitting of the stations is considered of major importance, since the inaccuracy of measurements due to inadequate representativeness, can be considerably larger to the one expected by each station separately. Therefore the range of each station should not exceed 10 km at maximum.
All stations are placed on land with even slopes, covered with grass, or a surface representative of the neighboring area, and surrounded by fencing, to block off trespassing.
The sites were selected to be far from trees, buildings, walls or other obstacles in present, as well as in the future. The distance of all obstacles from the rain gauges was selected to be at least twice the obstacle's height according to the WMO specifications.
Except from the rain gauges, all other sensors are placed on a stainless 6-meter weather mast, that holds to wind speeds up to 150 knots and with the appropriate, by the Greek regulations, lightnings protection system.
For the proper functioning of each station, the required power supply is provided through a solar panel, which is installed on the weather mast. By that, each station can be supplied for a period of at least 15 days with completely cloudy weather.
A data logger is installed on each station. This unit records in specified time intervals the measurements of all sensors, connected to it and stores them temporarily. Via mobile telephony, all measurements are transmitted to the central data base.
The general disposition of the stations sensors is as follows: