Group 1: Lightning Detection Technologies
– Lightning detection invented by Alexander Stepanovich Popov in 1894.
– Ground-based and mobile detectors calculate direction and severity of lightning.
– Space-based detectors on satellites locate lightning range, bearing, and intensity.
– Lightning Detection and Ranging (LDAR) network at the Kennedy Space Center.
– Discharges with significant energy in the high frequency (HF) range up to 30MHz.
– VLF lightning receivers pick up reflections from the ionosphere.
– Earth-ionosphere waveguide traps VLF- and ELF waves.
– Waveguide is dispersive, group velocity depends on frequency.
– Direction finding method allows locating lightning strikes up to 10000km.
Group 2: Limitations and Comparison with Weather Radar
– Ground-based networks underestimate flashes, especially at storm onset.
– Central device and precision timing source needed for multi-location systems.
– Mobile detectors may misinterpret lightning distance due to signal attenuation.
– Space-based networks provide slightly delayed information.
– Lightning detectors indicate electrical activity, while radar indicates precipitation.
– Radar can detect developing storms before lightning detectors.
– Lightning strikes can occur outside radar-recorded precipitation.
– Weather radar can suffer from masking effects by attenuation.
Group 3: Aviation Use and Portable Lightning Detectors
– Large airliners prioritize weather radar for detecting storms.
– Modern avionics systems include lightning detection for safety.
– Smaller aircraft use brands like Stormscope and Strikefinder.
– Strikefinder can differentiate between real strikes and signal bounces.
– Lightning detectors are lightweight and affordable for smaller aircraft.
– Inexpensive detectors have limitations in sensitivity and false signal detection.
– Professional detectors eliminate false signals through multiple sensing techniques.
– Optical sensors can detect intracloud flashes not visible to the human eye.
– Improved sensitivity in detecting cloud-to-ground lightning signals.
Group 4: Enhanced Lightning Detection and Benefits
– Addition of optical sensor and coincidence circuit.
– Elimination of false alarms caused by RF noise.
– Operation of RF sensor at higher sensitivity.
– Early warning capabilities for developing thunderstorms.
– Increased sensitivity for warning of distant storms.
– Prediction of microbursts through IC flash detection.
– Identification and tracking of thunderstorms.
– Storm chasers can use directional optical detectors.
Group 5: Storm Intensity Quantification and Tornado Prediction
– Flash rate is proportional to the 5th power of convective velocity.
– Small changes in cloud height result in significant changes in flash rate.
– Total lightning includes IC and CG flashes.
– Detection of IC discharges helps quantify storm intensity.
– Severe storms producing tornadoes have high lightning rates.
– Detection of IC lightning aids in identifying clouds with high tornado potential.
– Ability to detect IC lightning improves tornado prediction.
– IC detection is crucial for predicting tornadoes.
A lightning detector is a device that detects lightning produced by thunderstorms. There are three primary types of detectors: ground-based systems using multiple antennas, mobile systems using a direction and a sense antenna in the same location (often aboard an aircraft), and space-based systems. The first such device was invented in 1894 by Alexander Stepanovich Popov. It was also the first radio receiver in the world.
Ground-based and mobile detectors calculate the direction and severity of lightning from the current location using radio direction-finding techniques along with an analysis of the characteristic frequencies emitted by lightning. Ground-based systems can use triangulation from multiple locations to determine distance, while mobile systems can estimate distance using signal frequency and attenuation. Space-based detectors on satellites can be used to locate lightning range, bearing and intensity by direct observation.
Ground-based lightning detector networks are used by meteorological services like the National Weather Service in the United States, the Meteorological Service of Canada, the European Cooperation for Lightning Detection (EUCLID), the Institute for Ubiquitous Meteorology (Ubimet) and by other organizations like electrical utilities and forest fire prevention services.
