Propagation effects on lightning magnetic fields over hilly and mountainous terrain

Li, Dongshuai; Paknahad, Javad; Rachidi, Farhad; Rubinstein, Marcos; Sheshyekani, Keyhan; Zhang, Q.; Wang, Z.

doi:10.1109/isemc.2015.7256384

Cited by 9 publications

(8 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is worth noting that our 3‐D FDTD has been tested and validated by comparing its results with those obtained using a finite element method approach, and excellent agreement has been obtained [ Li et al , ; Paknahad et al , ].…”

Section: Adopted Models and Methods For The Analysissupporting

confidence: 78%

“…They noted that the location accuracy of the lightning location could be improved after considering such correction. More recently, Li et al [] have presented a preliminary analysis on the propagation effects along hilly terrain on lightning magnetic fields by using FDTD method and noted that the waveshape, peak value, and time delay of the magnetic fields can be significantly affected when propagating along a hilly terrain.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Analysis of lightning electromagnetic field propagation in mountainous terrain and its effects on ToA‐based lightning location systems

Azadifar

Rachidi

et al. 2016

JGR Atmospheres

View full text Add to dashboard Cite

In this paper, we analyze the propagation effects on lightning-radiated electromagnetic fields over mountainous terrain by using a three-dimensional (3-D) finite difference time domain (FDTD) method. We also discuss the time delay error in the time-of-arrival (ToA) technique currently used to locate lightning in detection networks, specifically. Furthermore, the accuracy of different approximate methods presented in the literature is discussed and tested by using our 3-D FDTD method. It is found that (1) the time delays and amplitudes of the lightning-radiated electromagnetic fields can be significantly affected by the presence of a mountainous terrain and associated diffraction phenomena; (2) for a finitely conducting ground, the time delay shows a slight increase with the increase of the observation distance, but the time delay resulting from the finite ground conductivity appears to be smaller than that caused by the mountainous terrain; and (3) the timing error associated with the ToA technique depends on the threshold times. Threshold times of 10% and 20% of the peak provide very similar results compared to those corresponding to the peak of the first derivative of the magnetic field, and the threshold time exceeds 50% of the initial rising amplitude of the signal. Furthermore, we have assessed the accuracy of two simplified methods (terrain-envelope method and tight-terrain fit method) to account for the time delays resulting from the propagation in a mountainous terrain. It is found that both methods result in time delays that are in reasonable agreement but always overestimating the results obtained using the full-wave 3-D FDTD approach for the perfectly conducting ground. These two methods represent interesting alternatives to account for the time delay over a nonflat terrain using the terrain model.

show abstract

Section: Adopted Models and Methods For The Analysissupporting

confidence: 78%

Section: Introductionmentioning

confidence: 99%

Analysis of lightning electromagnetic field propagation in mountainous terrain and its effects on ToA‐based lightning location systems

Azadifar

Rachidi

et al. 2016

JGR Atmospheres

View full text Add to dashboard Cite

show abstract

“…The developed FDTD simulation code has been thoroughly validated against results obtained using FEMs [44].…”

Section: B Fdtd Modelingmentioning

confidence: 99%

On Lightning Electromagnetic Field Propagation Along an Irregular Terrain

Azadifar

Rachidi

et al. 2016

IEEE Trans. Electromagn. Compat.

View full text Add to dashboard Cite

Abstract-In this paper, we present a theoretical analysis of the propagation effects of lightning electromagnetic fields over a mountainous terrain. The analysis is supported by experimental observations consisting of simultaneous records of lightning currents and electric fields associated with upward negative lightning flashes to the instrumented Säntis tower in Switzerland. The propagation of lightning electromagnetic fields along the mountainous region around the Säntis tower is simulated using a full-wave approach based on the finite-difference time-domain method and using the two-dimensional topographic map along the direct path between the tower and the field measurement station located at about 15 km from the tower. We show that, considering the real irregular terrain between the Säntis tower and the field measurement station, both the waveshape and amplitude of the simulated electric fields associated with return strokes and fast initial continuous current pulses are in excellent agreement with the measured waveforms. On the other hand, the assumption of a flat ground results in a significant underestimation of the peak electric field. Finally, we discuss the sensitivity of the obtained results to the assumed values for the return stroke speed and the ground conductivity, the adopted return stroke model, as well as the presence of the building on which the sensors were located.

show abstract

“…According to Figure 8, the time delay, peak value, waveshape, and amplitudes of the horizontal magnetic fields (H y ) are affected by the presence of the mountain. Although the effect of the mountain on the time delay (peak field and onset time) was negligible for point A, its effect on points B and C (right side of the hill) was significant [51]. The results represented in Figure 8 have been validated using canonical structures against the simulation results obtained in [51].…”

Section: Application: Models and Hypotheses Considered For Analysismentioning

confidence: 83%

“…Although the effect of the mountain on the time delay (peak field and onset time) was negligible for point A, its effect on points B and C (right side of the hill) was significant [51]. The results represented in Figure 8 have been validated using canonical structures against the simulation results obtained in [51]. The only difference was that the GPU was used and the dimensions were 1500 × 1500 × 1500 m in this study, whereas a CPU processor was used in [51].…”

Section: Application: Models and Hypotheses Considered For Analysismentioning

confidence: 89%

On the Efficiency of OpenACC-aided GPU-Based FDTD Approach: Application to Lightning Electromagnetic Fields

et al. 2020

View full text Add to dashboard Cite

An open accelerator (OpenACC)-aided graphics processing unit (GPU)-based finite difference time domain (FDTD) method is presented for the first time for the 3D evaluation of lightning radiated electromagnetic fields along a complex terrain with arbitrary topography. The OpenACC directive-based programming model is used to enhance the computational performance, and the results are compared with those obtained by using a CPU-based model. It is shown that OpenACC GPUs can provide very accurate results, and they are more than 20 times faster than CPUs. The presented results support the use of OpenACC not only in relation to lightning electromagnetics problems, but also to large-scale realistic electromagnetic compatibility (EMC) applications in which computation time efficiency is a critical factor.

show abstract

Propagation effects on lightning magnetic fields over hilly and mountainous terrain

Cited by 9 publications

References 18 publications

Analysis of lightning electromagnetic field propagation in mountainous terrain and its effects on ToA‐based lightning location systems

Analysis of lightning electromagnetic field propagation in mountainous terrain and its effects on ToA‐based lightning location systems

On Lightning Electromagnetic Field Propagation Along an Irregular Terrain

On the Efficiency of OpenACC-aided GPU-Based FDTD Approach: Application to Lightning Electromagnetic Fields

Contact Info

Product

Resources

About