Farhad Rachidi-Haeri

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Angle and amplitude estimation errors in magnetic direction finding, called site errors, are important sensor-specific errors in lightning location systems (LLS). They are known to be caused by nearby cables and overhead lines due to induced currents. Due ...

We present a new profile for the electrodes forming the radial transmission line of a switched oscillator (SWO). The profile is formed using a curvilinear orthogonal space based on a specific 2-D transformation called logarithmic-tangent. The proposed prof ...

In the first part of this paper, the rigorous theory describing the electromagnetic field radiated by a lightning return stroke over a two-layered conducting ground was presented and the exact expressions for the lightning electromagnetic fields were developed and discussed. In this part of the paper, the theory along with its time domain numerical evaluation algorithm is used for the assessment of the validity of simplified approaches proposed in the literature for the vertical electric and horizontal magn

Electromagnetic time reversal (EMTR) has been shown to be an efficient method for locating faults in AC and DC power grids. In the available literature, the back-propagation medium has been considered to have identical losses as the direct-time medium. How ...

In this paper, we investigate lightning return stroke electromagnetic fields and induced voltages on nearby overhead lines associated with an inclined lightning channel. The study is based on the Antenna Theory (AT) model, which is appropriately extended t ...

We present a review of theoretical methods to compute lightning-induced currents and voltages on buried cables. The evaluation of such induced disturbances requires the calculation of the electric field produced by lightning along the cable path. We show t ...

In this paper, we present a novel, high-resolution method, referred to as HRTR, for localizing underground objects. HRTR is based on a combination of the Time Reversal (TR) and Multiple Signal Classification (MUSIC) algorithms, and can be readily integrated with conventional ground-penetrating radar (GPR) systems without requiring any additional hardware. The proposed method offers significant advantages, particularly in achieving higher resolution, which enhances the ability to distinguish ground surface r

The polarity reversal of the lightning‐generated first sky wave as a function of the observation distance is studied using a novel approach combining the finite‐difference time domain (FDTD) method and the superposition principle of electromagnetic waves. ...

This paper presents a new method based on the electromagnetic time-reversal (EMTR) theory for locating faults in power networks. The applicability of the EMTR technique to locate faults is first discussed. Using the classical transmission-line equations in ...

In this paper, an analysis of electric and magnetic fields radiated by lightning first and subsequent return strokes to tall towers is presented. The contributions of the various components of the fields, namely, static, induction, and radiation for the electric field, and induction and radiation for the magnetic field are illustrated and discussed. It is shown in particular that the presence of a tower tends, in general, to increase substantially the electric and magnetic field peaks and their derivatives.

In this paper, direct lightning current measurements obtained on the Sntis Tower from June 1st, 2010 to May 31st, 2011 are used to evaluate the ability of the EUCLID lightning detection network to detect this type of lightning triggered by a tall tower in ...

The accuracy of approximate formulas for the evaluation of lightning electromagnetic fields above and inside a lossy ground is investigated taking as reference full-wave numerical results obtained using a parallel implementation of the finite-difference ti ...

We discuss in this paper the propagation of lightning current pulses along conical tall structures. Although the dominant mode of an infinitely long conical transmission line is transverse electric and magnetic (TEM), such a structure can also support high ...

The aim of this document is to provide an extended description and application guide of methods belonging to the so-called Numerical Electromagnetic Analysis (NEA) applied to the calculation of electromagnetic transients in power systems. As known, the acc ...

In this study we present, to the best of our knowledge, the first three-dimensional (3D) reconstruction of an upward lightning flash using combined very high frequency (VHF) interferometric and high-speed camera (HSC) observations. Based on this reconstruction, we estimate the 3D velocities of different pulse fronts along the channel branches. Comparable 3D reconstructions have previously been reported for downward lightning flashes [1].The Mt. Säntis Lightning Research Facility [2], located in the Appenzel

To overcome the multipath interference in locating transient electromagnetic (EM) radiation sources in an indoor environment, we propose a criterion that calculates the correlation between back-propagated signals from observation points, to be used in EM t ...

New general expressions relating lightning return stroke currents and far radiated electric and magnetic fields are proposed, taking into account the effect of an elevated strike object, whose presence is included as an extension to the transmission line ( ...

Lightning discharges, including cloud-to-ground (CG) and intracloud (IC) lightning, are known to emit electromagnetic pulses (EMPs) in a wide frequency band ranging from few Hz up to hundreds MHz [1]. During the breakdown and ionization processes (mostly f ...

In this paper, the impact of an increasing number of arbitrary electrical/electronic devices on the overall radiated emissions is investigated. Understanding and quantifying such an impact are prerequisites to the proper evaluation of electromagnetic compa ...

A closed time-reversal (TR) cavity has been considered a purely theoretical concept whose experimental realization was assumed to be impossible. In this article, we demonstrate that it is, in fact, possible to realize a closed TR cavity using a network of ...

Farhad Rachidi-Haeri

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Evaluation of Site Errors in LLS Magnetic Direction Finding Caused by Large Hills Using the 3D‐FDTD Technique

A New Set of Electrodes for Coaxial Quarter Wave Switched Oscillators

Lightning electromagnetic radiation over a stratified conducting ground: 2. Validity of simplified approaches

Assessment of the Influence of Losses on the Performance of the Electromagnetic Time Reversal Fault Location Method

An antenna-theory approach for modeling inclined lightning return stroke channels

Lightning-induced currents in buried coaxial cables

Enhanced GPR Imaging Using High-Resolution TR-MUSIC for Underground Object Localization

The Polarity Reversal of Lightning‐Generated Sky Wave

An Efficient Method Based on the Electromagnetic Time Reversal to Locate Faults in Power Networks

Current and electromagnetic field associated with lightning-return strokes to tall towers

Preliminary Comparison of Data from the Säntis Tower and the EUCLID Lightning Location System

On the Validity of Approximate Formulas for the Evaluation of the Lightning Electromagnetic Fields in the Presence of a Lossy Ground

On the Mechanism of Current Pulse Propagation Along Conical Structures: Application to Tall Towers Struck by Lightning

Guideline for Numerical Electromagnetic Analysis Method

Combining VHF and optical observations to reconstruct an upward flash

A Correlation-Based Electromagnetic Time Reversal Technique to Locate Indoor Transient Radiation Sources

Far-field-current relationship based on the TL model for lightning return strokes to elevated strike objects

Lightning interaction with the ionosphere

EMC Impact of Disturbances Generated by Multiple Sources

A Closed Time-Reversal Cavity for Electromagnetic Waves in Transmission Line Networks