How LINET works
How LINET works
LINET measures the electromagnetic waves which lightning strokes emit. The measurement is carried out via highly sensitive sensors which are arranged across the area to be measured with spacing of around 150 to 250 km. Since the electromagnetic emission of the lightning spreads at the speed of light, it reaches the sensors at different points in time. Although the difference is a matter of mere micro-seconds (µs), the exact calculation of the original emission location of the lightning stroke is possible. To this end, the data measured by every single sensor is transmitted to a central server via the internet. The server then calculates the exact geographical position for all the lightning strokes measured (the so-called “location”) and stores these in a database. The results are then made available to the customer in real time. This measurement method is also known as the “time-of-arrival” method.
However, LINET measures not only the position of the lightning stroke. It also records the strength and polarity of the strokes, and, in particular, the height of the intra-cloud strokes, and supplements the lightning data with a third dimension. This feature is unique around the world for low-frequency networks (VLF/LF) used for large areas.
More on the 3D-measurement of the emission heights of intra-cloud strokes...
The LINET hardware basically comprises two modules: the measuring stations and a central server. The measuring stations, consisting of a field antenna, a GPS sensor and a field processor, are set up in the area to be monitored with a baseline of around 150 to 250 km (recommended). The position of the server is irrelevant as long as a sufficiently fast and stable internet connection exists. A backup server at another location ensures the reliability and availability of the system. The redundant number of sensors constitutes a great advantage. Only the best signals have to be drawn upon for the calculation. As such, the malfunctioning of an individual sensor is insignificant for the overall quality of the lightning-detection system.
Thanks to the simple operation, a LINET measuring station is quickly and easily set up, as long as power (at least 30W) and a stable internet connection are available.
Within a regular LINET measurement network, the mean deviation (mean error) in the calculation of the position of the lightning stroke is less than 150 m. The fact that larger location errors are almost excluded is just as important. The quality of the information provided is regularly verified by comparing the LINET measurement data with strikes into towers whose geographical co-ordinates are known. The precision can be improved even further using a denser network. Thanks to this location accuracy, LINET is the quality leader amongst the commercial lightning-detection systems.
More on the location accuracy of LINET...