nowcast's lightning detection network LINET detects strike impact points accurately to within 75 meters (median). This derives from the sensitive measuring stations, its special lightning plotting algorithm and the correlation with data from lightning strikes into towers of known position.
LINET measures the electromagnetic waves from lightning strokes. Those are detected by the highly sensitive sensors which are sited in the area of interest, spaced between 150 km and 250 km apart. How does the locating of lightning work? Due to the fact that the electromagnetic waves emitted by a lightning stroke are travelling through the atmosphere at the speed of light, they reach the sensors at slightly different moments. Although the arrival time differs by several microseconds only, the sensors can register it precisely, because all sensors are synchronized via GPS to an accuracy of nanoseconds. The measured data of every sensor is continuously being transmitted to the central server via the internet. Once the server has received the time stamps from all sensors, it is able to calculate the position of the flash. The resulting lightning data – time stamp, exact geographic location, amplitude (8kA), type (ground stroke or cloud stroke), height (of cloud strokes only) – is at the user’s command only a few seconds later. This method is known as “Time of Arrival”.
The measuring stations consist of a special magnetic antenna, a GPS module and a processor. The antenna is optimized for receiving electromagnetic waves – similar to a radio antenna. The exact time is recorded by the GPS module – accurately to within 10 nanoseconds. The processor converts the analog signals into digital signals, combines them with the time stamp of the GPS module and sends the data to the central server via the internet.
The quality of the location accuracy is constantly being controlled by data verification with strikes into towers and measuring systems of known position.