Thunderstorm sensor and method of identifying and locating thunderstorms

Abstract

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.