A lightning detector is equipment whose main function is to sense lightning during thunderstorms to prevent human casualty and minimize damage to commercial and residential property. Lightning detectors can be classified according to size, capacity and installation location and methods. There are four major categories of lightning detectors and they are the following:

Ground-Based Lightning Detection Systems

This variant uses multiple antennas separated by hundreds of kilometers to detect the pulses of radio frequency that are produced by a lightning bolt. For this reason, they are often called RF or Radio Frequency detectors.

In a lightning flash, electromagnetic pulses travel outward from the bolt to the ground at a vast speed. Since the antennas are spread over a large area on the ground, these antennas become the basis for triangulation. This system ensures that the exact position of the lightning flash can be pinpointed. Radio direction-finding protocols give the system the capability to determine the severity of the lightning flash.

Mobile Lightning Detection Systems

This type of lightning detection system is portable and can be easily moved from one place to another. The lightning detection apparatus is usually mounted on a moving vehicle (usually an aircraft). What such lightning detection systems do is estimate the strength of the original lightning signal from the exponential decrease in strength as it passes through the detector's signal strength-detection apparatus.Lightning Detector

Space-Based Lightning Detection Systems

This variant of light detection equipment uses satellites to directly measure the severity, the position and the direction of lightning. Such systems have a 'visual' on the lightning through the camera systems and other sensory equipment aboard the satellites. NASA launched such a system in 1995 to monitor lightning activity. The Lightning Imaging Sensor, which analyzes a lightning's position through rainfall activity, was launched two years later.

Personal Lightning Detection Systems

There are also personal lightning detectors which are ideal for personal use. They are small enough to be carried around by people whose occupation or activities require them to be outdoors most of the time. People who usually carry personal lightning detectors are golfers, law enforcement officials and sports officials.

Unlike the other detection systems, personal detectors work by picking up the electromagnetic pulse (EMP) emitted by a lightning strike; by gauging the strength of the EM pulse, the detector can estimate how far away the strike was. Some advanced personal lightning detection systems can also estimate the path of a thunderstorm through inputs from multiple lightning flashes.

Personal lightning detectors have a very limited range, compared to their more robust cousins of ground, mobile or space-based systems. For example, personal detectors cannot pinpoint where the thunderstorm is coming from and it cannot detect lightning strikes which are out of its range. Moreover, since a personal lightning detector is triggered by EMP, other EMP devices such as electronic equipment, fluorescent lamps, car engines and appliances) can affect the personal lightning detector. In spite of these perceived limitations, however, personal lightning detectors remain useful as an early-warning and lightning-detection device.