An electromagnetic field analysis method for an anisotropic conductive material involves using an analysis grid having a first side and a second side that are orthogonal to each other to analyze an electromagnetic property of an anisotropic conductive material in which conductivity in a first direction is different from conductivity in a second direction. One or both of the first direction and the second direction are parallel to a direction different from either one of the first side and the second side of the analysis grid. One electromagnetic field component located on the first side and extending along the second side is calculated based on electromagnetic field components that are located on a plurality of the second sides surrounding the one electromagnetic field component and that extend along the second sides.

A method for warning about lightning activity in wind farms which is suitable for predicting the generation of upward lightning originating from the wind-driven power generators the wind farm and for warning about the possible generation is provided. To that end, in the method the presence or absence of a storm cell in the wind farm and/or in the vicinity thereof, within a radius of less than 400 km, is detected; the local electric field in the wind farm is measured, at least one atmospheric condition is identified or measured under given premises, and the probabilities of the generation of upward lightning originating from the wind-driven power generators of the wind farm are determined depending on the result of the measurements, identifications and detections, a warning signal being transmitted in the event that the determined probability exceeds a given threshold value.

A device comprises a circuit board, a Rogowski coil on the circuit board, persistent data storage on the circuit board, and a control circuit on the circuit board for collecting values representing current sensed by the coil, and storing the values in the persistent memory.

The invention relates to a device for detecting electrical currents on or in the vicinity of electrical conductors with at least one Reed switch as a magnetically responsive switch, which is arranged in the vicinity of the electrical conductor such that, when there is a significant current flow through the conductor, the magnetic field created triggers the switch and initiates an evaluation electronics connected to the switch. For the detection of surge current variables and the differentiation between long-term pulsed currents and short-term pulsed currents, a plurality of Reed switches are arranged at a predetermined distance from the electrical conductor, wherein the evaluation electronics determines the response and the switching times of the respective Reed switches, determines die surge current variable from the allocation of the determined values to the respective Reed switch and the pulse form from the switching time, wherein, for the purpose of adjusting the response behavior, at least one of the Reed switches comprises a shielding for influencing the magnetic field acting on the respective Reed switch.

A broadband interferometer lightning positioning method based on pulse matching and a system thereof that improves the positioning accuracy of the interferometer to the lightning radiation source. The method includes acquiring a very high frequency radiation pulse signal set of lightning; determining a first very high frequency radiation pulse signal within a set time period as a reference pulse signal; determining a first comparison pulse signal, and determining a second comparison pulse signal; moving both the first comparison pulse signal and the second comparison pulse signal to the position corresponding to the reference pulse signal using the cross-correlation algorithm to obtain a pulse signal set, simultaneously covering each pulse signal in the pulse signal set using a sliding window with a set width to determine the position of the lightning radiation source.

This disclosure describes a system and method for generating images by performing TEM surveys using pre-existing infrastructure such as transmission lines, or power lines, and naturally occurring transients such as lightning strikes or load switching. A relatively inexpensive sensor array can be installed on overhead power lines (e.g., electrical transmission or sub-transmission lines) which can detect transients in the overhead power lines. Transients in the overhead power lines can cause the power lines to emit pulses of electromagnetic (EM) radiation, which propagate into the earth's subsurface. This sudden change in electromagnetic field in the subsurface can induce eddy currents, which in turn emit return EM radiation that can propagate back to the overhead power line and induce secondary voltage and current transients. The magnitude of these secondary transients, and their time delay from the original transient are influenced by the properties of the subsurface in which the eddy currents formed.

A portable electronic device for detecting an electromagnetic pulse generated by a tesla coil, and selectively a pulse from natural lightning. The device has a detection circuit for electromagnetic pulses, operating to detect an observed electromagnetic pulse having a frequency at least within a range of about 50 kilohertz (kHz) to about 300 megahertz (MHz). The detection circuit generate an output signal corresponding to the observed electromagnetic pulse. A microcontroller analyzes the output signal from the detection circuit against a tesla profile that identifies a detected electromagnetic pulse as a tesla coil pulse when the observed electromagnetic pulse has a frequency within the range of about 50 kHz to about 300 MHz with a pulse duration of at least 0.50 seconds. The microcontroller then generates an indication that the detected electromagnetic pulse is that of a tesla coil, and generates a tesla coil alert, typically flashing of an LED.

According to one implementation, an aviation system 100 includes electric field sensors 112 and a ground system 114 including a computer configured to communicate with each of the electric field sensors 112. The computer is configured to: acquire electric field intensities from the electric field sensors 112 respectively, and generate a first electric field distribution on a ground surface 16 based on the electric field intensities; derive a matrix; derive a pseudo inverse matrix of the matrix; derive an electric charge distribution on the horizontal plane by multiplying the pseudo inverse matrix by the first electric field distribution on the ground surface 16; and derive a second electric field distribution on a flight path based on the electric charge distribution. The first electric field distribution on the ground surface 16 is derived by multiplying the matrix by electric charges temporarily set on a horizontal plane at a predetermined altitude.

A system and method for detecting electrical events, often a corona associated with an impending lightning strike, including a coupling mechanism configured to establish an electromagnetic connection with a conductive substrate to receive signals intercepted by the conductive substrate. A detector circuit converts and discriminates the received signals into output signals. An output mechanism records and/or transmits the output signals, as well as determines if the output signal represents a qualified event signal.

This disclosure describes a system and method for generating images by performing TEM surveys using pre-existing infrastructure such as transmission lines, or power lines, and naturally occurring transients such as lightning strikes or load switching. A relatively inexpensive sensor array can be installed on overhead power lines (e.g., electrical transmission or sub-transmission lines) which can detect transients in the overhead power lines. Transients in the overhead power lines can cause the power lines to emit pulses of electromagnetic (EM) radiation, which propagate into the earth's subsurface. This sudden change in electromagnetic field in the subsurface can induce eddy currents, which in turn emit return EM radiation that can propagate back to the overhead power line and induce secondary voltage and current transients. The magnitude of these secondary transients, and their time delay from the original transient are influenced by the properties of the subsurface in which the eddy currents formed.