All the sensors of the Austrian Lightning Detection & Information System ALDIS have been renewed completely in 2006. Today ALDIS employs the so called LS7000 Sensor manufactured by VAISALA Inc. This type of sensors is comparable with the previously used IMPACT sensor measuring angle and time. Main changes are due to fully digital signal processing. Fig.1 shows the locations of the eight LS7000 sensors employed in the ALDIS network. ADSL communication is used for data transfer between the sensors and the central processor.
1: Location of the direction finder in Austria
The direction finders used in Austria have a mean detection range of about 400 km. Due to the high density of direction finders in the Austrian lightning detection system some redundant information about the discharges in Austria is collected. A high number of flashes is located by four or even more DF. This network configuration allows to achieve a median location accuracy better then 500 meters.
All the lightning data are stored on a UNIX-workstation by the software package CATS (Computer Aided Thunderstorm Surveillance System), which was developed by a company METEORAGE. This company also operates the French lightning detection system.
CATS stores the flash data permanently in a continuous database. By requests to this database it is easy to perform data analysis for short but also for long time periods (e.g. statistics over several years).
Besides the data recording, the CATS workstation is used as a server for the online users of the lightning location system. The online display runs on a PC connected by different kinds of communication lines to the ALDIS server.