In order for there to be increased detection, it is better at times to combine a few detection methods to achieve better results. The new lightning detection sensors being created use Magnetic Direction Finding methods as well as Time Of Arrival methods. This method is also known as the Combined method because of the combination of the two methods.
Magnetic Direction Finding methods use two sensors to detect a lightning strike. These sensors detect the azimuth which basically means the they calculate the angle between north and the direction towards the lightning strike. When a lightning strikes it creates an electric field. This electric field in turn creates a magnetic field which is always perpendicular to the electric field. When two or more sensors are used the lightning direction can be calculated.
Time Of Arrival uses three sensors to determine the exact location of the lightning strike. Each one of the sensors has GPS installed in it so it knows the exact location as well as time in UTC.
When the combined method is used only two sensors are used to determine the location of the lightning. More sensors are used to improve on the accuracy of determining the time as well as the position of the lightning strike.