Vaisala Oyj

Lightning Location and Protection, Inc.

Lightning Protection Technology

Alburt E Pifer

Kenneth L Cummins

Martin J Murphy

Leon G Byerley, Iii

Wolfgang Schulz

Dion W Howard

Kenneth Hufnagel

William Hiscox

E Philip Krider

A lightning detection system provides an estimated location of a lightning stroke. The system includes sensors, and an analyzer. Each sensor provides messages having sensor identification, an amplitude responsive to the lightning stroke, and a time of detecting the lightning stroke. The analyzer applies time corrections and amplitude corrections to improve the accuracy of determining the location of the lightning stroke. Time adjustments and amplitude adjustments for the time and amplitude corrections are recalled from a matrix accessed according to a suggested or estimated location. The matrix may be organized by coordinates of longitude and latitude.

Systems and methods for time corrected lightning detection

A lightning detection and data acquisition system. A plurality of remote programmable sensor is utilized to detect cloud to ground and IC lightning strikes. Analog representations of the lightning strikes are converted to digital signals. The digital signals are classified according to user changeable criteria. The classified digital signals are compressed and optionally decimated. The compressed information is transmitted to a central location where it is decompressed and used to correlate the location, magnitude, and travel path of the detected lightning strikes.

Lightning detection and data acquisition system

An efficient optical radiation detector for lightning or other light signals such as pulses, bursts, flashes, and steady fluctuations. A silicon photodiode (or similar light-sensitive silicon device) is arranged to receive light signals (infrared, visible, ultraviolet, broadband, etc.) of interest. The photodiode is connected across the primary winding of a properly-designed transformer. The transformer-coupled photodiode circuit gives AC coupling, photodiode bias, voltage gain, and several other desirable detector characteristics. Light fluctuations on the photodiode produce variations of photocurrent in the transformer primary circuit which, in turn, induce current in the secondary winding and circuit of the transformer. The current induced in the secondary circuit of the transformer is used to do useful work (such as energize an audible alarm, increment a counter, latch a relay, etc.) or it is further amplified and processed, or combined with other signals to make an event detector such as a lightning sensor. The transformer-coupled photodiode circuit provides a general purpose light-change detector that is particularly useful as the optical sensor element of a lightning detector including any of a variety of so-called 'lightning coincidence detectors'. The chance of a 'false' lightning detection is greatly reduced by the combination of an electric or magnetic field-change detection device with the transformer-coupled photodiode circuit.

Transformer-coupled photodiode circuit for lightning and other light

An omnidirectional lightning ranging, identification and protection system having circuits that produce no false alarms or failures to alarm, responsive to cloud to ground and cloud discharges, capable of differentiating between cloud to ground and cloud discharges insensitive to background noise, autonomous with respect to power and communications conductors for operating reliably in the presence of nearby lightning discharges, requiring no field calibration, that provides local and remote lightning rate and range data, and that provides mechanisms for automatically signalling and disconnecting electrical equipment for the purpose of lightning protection. The system has circuits that are responsive to the electric field changes produced by lightning discharges in the frequency range between 2 khz and about 200 khz and to time coincident optical radiation in the 6000 to 9000 angstroms wavelength range. The sensor has circuits for receiving and manipulating the optical radiation component, circuits for receiving and manipulating the radiation field component and electrostatic field component, and other control circuits for generating the active and inactive states and for controlling a photovoltaic solar power source, and circuits for generating digital signals that produce encoded data representing the occurrence, type and range to signal sources of natural lightning origin and circuits for communicating the composite data signal to a remote controller for further processing and manipulation.

Autonomous electro-optical lightning identification and ranging

A synchronization system and method for a lightning location system having a plurality of remote lightning detectors transmitting data to a lightning position analyzer via a communication system having variable transmission delays. Each lightning detector includes a clock for identifying the time of occurrence of a lightning event such as cloud to ground lightning discharge, the time of occurrence data being transmitted to the position analyzer along with other data representing the lightning event. The position analyzer also includes a clock for identifying the time of arrival at the analyzer of data representing a lightning event. Lightning events are correlated by the position analyzer by comparing the time intervals between the occurrence of lightning events detected by one detector and the time intervals between the occurrence of lightning events detected by a second detector. The dfference between the time of occurrence of a lightning event detected by the one detector and the time of occurrence of a correlated lightning event detected by the second detector is used as a correction factor to synchronize the two detectors. Synchronized detectors are synched to the position analyzer clock by using the minimum difference between the time of arrival of data representing a lightning event and the time of occurrence of the lightning event detected by a synchronized detector.

System and method for synchronizing lightning detectors

The thunderstorm sensor of the present invention includes a pair of orthogonally positioned magnetic loop antennas to provide signals representative of the north-south and east-west components of the magnetic field produced by a lightning discharge. The system also includes an omni-directional electric field antenna to provide a signal representative of the electric field produced by a lightning discharge. The magnetic field and electric field signals from the antennas are coupled to an analog signal processor and digitizer which provides digital representations of the peak north-south and peak east-west components of the radiated magnetic field. The analog signal processor and digitizer also provides digital representations of the peak radiated electric field and the electric field sampled at a time subsequent to the time of occurrence of the peak radiated field wherein the second sampled electric field value represents the electrostatic field change due to the lightning discharge. The amplitude of the magnetic field is determined from the digital representations of the north-south and east-west components of the magnetic field. The relative electric field change is determined from the ratio of the second sampled electric field to the peak radiated electric field. The amplitude of the magnetic field and the relative electric field change are compared to respective first and second reference values to determine whether the detected lightning is associated with a thunderstorm within one or more predetermined ranges of the sensor.

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Tucson, AZ, United States of America

Alburt E Pifer