scholarly journals Comparing the Wave Characteristics of Breakdown Pulses of the Lightning Waveforms in the Himalayan Region

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Pitri Bhakta Adhikari ◽  
Aashutosh Adhikari
Keyword(s):  
Rise Time ◽  
Pulse Train ◽  
Amplitude Ratio ◽  
Pulse Amplitude ◽  
Himalayan Region ◽  
Time Interval ◽  
Return Stroke ◽  
Zero Crossing ◽  
Wave Characteristics ◽  
Crossing Time

We have analyzed the breakdown pulse train with or without the main event in this paper. Among the selected 81 flashes, 36 flashes are starting positively, and 45 are starting negatively. Also, 58 flashes contain positive pulses, and 67 flashes contain negative pulses, whereas 44 flashes contain both positive and negative pulses. Among these 81 flashes, 22 flashes follow the main events, and the rest are isolated events. In this study, we got the main duration of PB pulses as 1.94 ms and the time interval between the breakdown pulse and return stroke as 61.49 ms. On taking each pulse train, we found the rise time to be 2.6 μs, zero-crossing time 14.95 μs, and the time interval between pulses 199.3 μs. The largest pulse amplitude ratio in the preliminary breakdown pulse to the main event return stroke was 0.43.

Review and Evaluation of Characterization First Return Stroke in the Measured Lightning Electric Fields on Malaysia Data

2015 ◽  
Vol 793 ◽  
pp. 44-48
Author(s):  
S.N.M. Arshad ◽  
Mohd Zainal Abidin Ab Kadir ◽  
Mahdi Izadi ◽  
A.M. Ariffen ◽  
M.N. Hamzah ◽  
...  
Keyword(s):  
Electric Fields ◽  
Rise Time ◽  
Statistical Correlation ◽  
Peak Time ◽  
Return Stroke ◽  
Zero Crossing ◽  
Time To Peak ◽  
Lightning Channel ◽  
Crossing Time

In this paper, the characterization of measured electric fields on first return stroke due to lightning channel was studied done. Likewise, previous studies on this case were discussed and reviewed accordingly. Furthermore, the first return stroke was analyzed done in detailed and was indicated on the real measured electric fields. Later the results were discussed appropriately. The behaviorsof first return stroke signal has beencharacterized from previous researchers. This study shows themeasured data in detailed, which include there are slow front time, first return stroke peak, time to peak, zero crossing time and 10% to 90% rise time. The characteristic of first return stroke signal data in Malaysia was compared with data gathered in Sweden. Moreover In addition, the statistical correlation between electric field zero times and corresponding rise times was also been studied.

scholarly journals An analysis of manual and autoanalysis for submicrosecond parameters in the typical first lightning return stroke

2021 ◽  
Vol 23 (3) ◽  
pp. 1451
Author(s):  
Muhammad Akmal Bahari ◽  
Zikri Abadi Baharudin ◽  
Tole Sutikno ◽  
Ahmad Idil Abdul Rahman ◽  
Mohd Ariff Mat Hanafiah ◽  
...  
Keyword(s):  
Feature Extraction ◽  
Detection System ◽  
Programming Technique ◽  
Return Stroke ◽  
Zero Crossing ◽  
Manual Analysis ◽  
Lightning Detection ◽  
Crossing Time ◽  
Rising Time ◽  
Initial Peak

The mechanism on how lightning detection system (LDS) operated never been exposed by manufacturer since it was confidential. This scenario motivated the authors to explore the issue above by using MATLAB to develop autoanalysis software based on the feature extraction. This extraction is intended for recognizing the parameters in the first return stroke, and compare the measurement between the autoanalysis software and the manual analysis. This paper is a modification based on a previous work regarding autoanalysis of zero-crossing time and initial peak of return stroke using features extraction programming technique. Further, the parameter on rising time of initial peak is added in this autoanalysis programming technique. Finally, the manual analysis using WaveStudio (LeCroy product) of those two lightning parameters is compared with autoanalysis software. This study found that the autoanalysis produce similar result with the manual analysis, hence proved the reliability of this software.

scholarly journals The Energy, Momentum, and Peak Power Radiated by Negative Lightning Return Strokes

Atmosphere ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1288
Author(s):  
Vernon Cooray ◽  
Andre Lobato
Keyword(s):  
Radiation Field ◽  
Peak Power ◽  
Outer Space ◽  
Cylindrical Symmetry ◽  
Return Stroke ◽  
Zero Crossing ◽  
Radiation Fields ◽  
Radiated Energy ◽  
Crossing Time ◽  
Energy And Momentum

Electromagnetic radiation fields generated by return strokes transport both energy and momentum from the return stroke to outer space. The momentum transported by the radiation field has only a vertical or z component due to azimuthal symmetry (cylindrical symmetry) associated with a vertical return stroke. In this paper, the energy, momentum, and peak power radiated by return strokes as a function of the return stroke current, return stroke speed, and the zero-crossing time of the radiation fields are studied. The results obtained by numerical simulations for the energy, vertical momentum, and the peak power radiated by lightning return strokes (all parameters normalized by dividing them by the square of the radiation field peak at 100 km) are the following: A typical first return stroke generating a radiation field having a 50 μs zero-crossing time will dissipate field normalized energy of about (1.7–2.5) × 103 J/(V/m)2 and field-normalized vertical momentum of approximately (2.3–3.1) × 10−6 Kg m/s/(V/m)2. A radiation field with a zero-crossing time of 70 μs will dissipate about (2.6–3.4) × 103 J/(V/m)2 in field-normalized energy and (3.2–4.3) × 10−6 Kg m/s/(V/m)2 in field-normalized vertical momentum. The results show that, for a given peak radiation field, the radiated energy and momentum increase with increasing zero-crossing time of the radiation field. The normalized peak power generated by a first return stroke radiation field is about 1.2 × 108 W/(V/m)2 and the peak power is generated within about 5–6 μs from the beginning of the return stroke. Conversely, a typical subsequent return stroke generating a radiation field having a 40 μs zero-crossing time will dissipate field-normalized energy of about (6–9) × 102 J/(V/m)2 and field-normalized vertical momentum of approximately (7.5–11) × 10−7 Kg m/s/(V/m)2. The field-normalized peak power generated by a subsequent return stroke radiation field is about 1.26 × 108 W/(V/m)2 and the peak power is generated within about 0.7–0.8 μs from the beginning of the return stroke. In addition to these parameters, the possible upper bounds for the energy and momentum radiated by return strokes are also presented.

scholarly journals A Comparative Study on the Positive Lightning Return Stroke Electric Fields in Different Meteorological Conditions

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Chin-Leong Wooi ◽  
Zulkurnain Abdul-Malek ◽  
Behnam Salimi ◽  
Noor Azlinda Ahmad ◽  
Kamyar Mehranzamir ◽  
...  
Keyword(s):  
Electric Fields ◽  
Rise Time ◽  
Opposite Polarity ◽  
Cumulative Probability ◽  
Return Stroke ◽  
Zero Crossing ◽  
Tropical Regions ◽  
Front Duration ◽  
First Time ◽  
Positive Return

Positive cloud-ground lightning is considerably more complex and less studied compared to the negative lightning. This paper aims to measure and characterize the significant parameters of positive return strokes electric field, namely, the zero-to-peak rise time, 10–90% rise time, slow front duration, fast transition rise time (10–90%), zero-crossing time, and opposite polarity overshoot relative to peak. To the best of the authors’ knowledge, this is the first time such detailed characteristics of positive lightning in Malaysia are thoroughly analyzed. A total of 41 positive lightning flashes containing 48 return strokes were analyzed. The average multiplicity is 1.2 strokes per flash. The majority of positive lightning was initiated from the primary positive charge rather than as a byproduct of in-cloud discharges. The cumulative probability distribution of rise time parameters, opposite polarity overshoot relative to peak, and slow front amplitude relative to peak are presented. A comparison between studies in four countries representing tropic, subtropic, and temperate regions was also carried out. Measured parameters in Florida, Sweden, and Japan are generally lower than those in Malaysia. Positive lightning occurrences in tropical regions should be further studied and analyzed to improve our current understanding on positive return strokes.

Investigation of Zero Crossing Detection for First Return Stroke in Negative Cloud-to-Ground Lightning Flash

2019 ◽  
Vol 11 (3) ◽  
Author(s):  
Ahmad Idil Abd Rahman ◽  
◽  
Muhammad Akmal Bahari ◽  
Zikri Abadi Baharudin ◽  
◽  
...  
Keyword(s):  
Lightning Flash ◽  
Return Stroke ◽  
Zero Crossing ◽  
Cloud To Ground Lightning

scholarly journals COMPARISON BETWEEN THE RESULTS OF LITTORAL-DRIFT COMPUTATIONS AND CUBATURE OF DEPOSITS IN A DREDGED CHANNEL

1974 ◽  
Vol 1 (14) ◽  
pp. 42
Author(s):  
V.F. Motta ◽  
J.V. Bandeira
Keyword(s):  
Time Interval ◽  
Littoral Drift ◽  
Monthly Basis ◽  
Wave Characteristics ◽  
Order Of Magnitude ◽  
Annual Volume ◽  
Offshore Oil ◽  
Remarkable Agreement

The total annual volume of littoral drift on either side of the mouth of Sergipe estuary, in the Northeast of Brazil, has been de_ termined by applying Caldwell's, Castanho's and Bijker's methods to the wave characteristics that had been recorded at a twenty-metre depth of water, over a whole year, for the design of an offshore oil terminal. The three computation methods yielded the same order of maj> nitude which was found to amount to about 80000Om^/year. The dominant drift is s outhwes tward, and its predicted amount is 660000m-*/year. It was also found that although the three methods lead to total re suits of the same order of magnitude, they do not agree as to the vari^ ation of littoral drift over the year for the s ame waves. An eight-metre deep shipping channe 1 has been dredgedaccross the bar. The channel was surveyed in December 1971, August and Decem ber 1972, and a cubature of the deposits was made after the littoraldrift computations had been carried out. As the latter had been per formed on a monthly basis, a comparison became possible between pre dieted and actual volumes of deposits for the same lengths of time. The predicted volumes for the whole year were found to be from 34 to 46% greater than the actual results. However, for the time interval August-December 1972 a remarkable agreement was found be^ tween predicted and actual results.

Characterization of interbedded thin beds using zero-crossing-time amplitude stratal slices

Geophysics ◽  
2015 ◽  
Vol 80 (5) ◽  
pp. N23-N35 ◽  
Author(s):  
Guofa Li ◽  
Mauricio D. Sacchi ◽  
Yajing Wang ◽  
Hao Zheng
Keyword(s):  
Zero Crossing ◽  
Crossing Time

Determination of source parameters of small earthquakes from P-wave rise time

1973 ◽  
Vol 63 (2) ◽  
pp. 599-614 ◽  
Author(s):  
M. E. O'Neill ◽  
J. H. Healy
Keyword(s):  
Rise Time ◽  
Source Parameters ◽  
P Wave ◽  
Simple Method ◽  
Zero Crossing ◽  
Basic Measurement ◽  
Earthquake Source Parameters ◽  
Short Period ◽  
Stress Drops

abstract A simple method of estimating source dimensions and stress drops of small earthquakes is presented. The basic measurement is the time from the first break to the first zero crossing on short-period seismograms. Graphs relating these measurements to rise time as a function of Q and instrument response permit an estimate of earthquake source parameters without the calculation of spectra. Tests on data from Rangely, Colorado, and Hollister, California, indicate that the method gives reasonable results.

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