Performance Improvements of Lightning Detection Systems and Its Expected Roles

2019 ◽  
Vol 139 (8) ◽  
pp. 526-529
Author(s):  
Kazuo YAMAMOTO
Keyword(s):  
Performance Improvements ◽  
Detection Systems ◽  
Lightning Detection

scholarly journals Effect of indirect lightning strike to 66kV transmission line in Java-Bali system

2018 ◽  
Vol 197 ◽  
pp. 11001
Author(s):  
Aristo Adi Kusuma ◽  
Putu Agus Aditya Pramana ◽  
Brian Bramantyo S.D.A. Harsono ◽  
Buyung Sofiarto Munir
Keyword(s):  
Transmission Line ◽  
Transmission Lines ◽  
Lightning Strike ◽  
Actual Condition ◽  
Peak Current ◽  
Lightning Strikes ◽  
Detection Systems ◽  
Current Magnitude ◽  
Lightning Detection ◽  
Insulator Flashover

Based on Java-Bali grid disturbance data, the 66kV transmission lines that is close to or intersect with 150kV or 500kV transmission line is often experienced earth fault due to insulator flashover. The insulator flashover can be caused by indirect lightning strike since lightning strikes tend to strike higher structure. Therefore, this paper will determine the effect of indirect lightning strike on 150kV or 500kV transmission line to 66kV transmission line by modeling and simulation using application of transient analysis. Variation of lightning peak current magnitude and gap between 66kV transmission line and transmission line with higher voltage is performed during simulation. The range of peak current magnitude follows the data from lightning detection systems, while the value of gap follows the data from actual condition. It is found that higher current peak and closer gap will cause higher transient overvoltage on insulator of 66kV transmission line thus insulator flashover may occur more frequent. Addition of earth wire on 66kV transmission line and gap between each transmission by organizing the sag of conductor can be performed to minimize the insulator flashover.

scholarly journals Lightning Monitoring Integrated System

2019 ◽  
Author(s):  
Michell Cruz ◽  
Marcio Lopes ◽  
Alen Vieira ◽  
Flávio Santos ◽  
Ricardo Shinkai ◽  
...  
Keyword(s):  
Real Time ◽  
Satellite Images ◽  
Integrated System ◽  
Decision Makers ◽  
Natural Phenomenon ◽  
Tabular Data ◽  
Web Based ◽  
Detection Systems ◽  
Lightning Detection ◽  
Intuitive Interface

Lightning is a natural phenomenon and presents severe risks to people and animals, as well as affects several segments of the productive sector. A web-based lightning monitoring system has been developed to integrate different lightning detection systems, as well as to generate spatial and tabular data and products, capable of assisting specialists and decision makers. The system also allows combining lightning data with satellite images, increasing the capacity of analysis in near real time. This tool proved to be stable and efficient, with an intuitive interface that facilitates interaction with users.

The Relationship between Total Cloud Lightning Behavior and Radar-Derived Thunderstorm Structure

2013 ◽  
Vol 28 (1) ◽  
pp. 237-253 ◽  
Author(s):  
Eric Metzger ◽  
Wendell A. Nuss
Keyword(s):  
Weather Type ◽  
Severe Weather ◽  
Characteristic Change ◽  
Lightning Flash ◽  
Fort Worth ◽  
Detection Systems ◽  
Lightning Detection ◽  
Rapid Changes ◽  
Total Lightning ◽  
The Relationship

Abstract Total lightning detection systems have been in development since the mid-1980s and deployed in several areas around the world. Previous studies on total lightning found intra- and intercloud lightning (IC) activity tends to fluctuate significantly during the lifetime of thunderstorms and have indicated that lightning jumps or rapid changes in lightning flash rates are closely linked to changes in the vertical integrated liquid (VIL) reading on the National Weather Service’s Weather Surveillance Radar-1988 Doppler (WSR-88D) systems. This study examines the total lightning and its relationship to WSR-88D signatures used operationally to determine thunderstorm severity to highlight the potential benefit of a combined forecast approach. Lightning and thunderstorm data from the Dallas–Fort Worth, Texas, and Tucson, Arizona, areas from 2006 to 2009, were used to relate total lightning behavior and radar interrogation techniques. The results indicate that lightning jumps can be classified into severe wind, hail, or mixed-type jumps based on the behavior of various radar-based parameters. In 25 of 34 hail-type jumps and in 18 of 20 wind-type jumps, a characteristic change in cloud-to-ground (CG) versus IC lightning flash rates occurred prior to the report of severe weather. For hail-type jumps, IC flash rates increased, while CG flash rates were steady or decreased. For wind-type jumps, CG flash rates increased, while IC flash rates either increased (12 of 18) or were steady or decreased (6 of 18). Although not every lightning jump resulted in a severe weather report, the characteristic behavior in flash rates adds information to radar-based approaches for nowcasting the severe weather type.

scholarly journals A Bayesian Approach to Assess the Performance of Lightning Detection Systems

2016 ◽  
Vol 33 (3) ◽  
pp. 563-578 ◽  
Author(s):  
Phillip M. Bitzer ◽  
Jeffrey C. Burchfield ◽  
Hugh J. Christian
Keyword(s):  
North America ◽  
Detection System ◽  
Optical Detectors ◽  
Bayesian Techniques ◽  
Detection Systems ◽  
Lightning Detection ◽  
Spatial Domains ◽  
Stroke Type ◽  
Total Lightning ◽  
Imaging Sensor

AbstractHistorically, researchers explore the effectiveness of one lightning detection system with respect to another system; that is, the probability that system A detects a discharge given that system B detected the same discharge is estimated. Since no system detects all lightning, a more rigorous comparison should include the reverse process—that is, the probability that system B detects a discharge given that system A detected it. Further, the comparison should use the fundamental physical process detected by each system. Of particular interest is the comparison of ground-based radio frequency detectors with space-based optical detectors. Understanding these relationships is critical as the availability and use of lightning data, both ground based and space based, increases. As an example, this study uses Bayesian techniques to compare the effectiveness of the Earth Networks Total Lightning Network (ENTLN), a ground-based wideband network, and the Lightning Imaging Sensor (LIS), a space-based optical detector. This comparison is completed by matching LIS groups and ENTLN pulses, each of which correspond to stroke-type discharges. The comparison covers the period from 2009 to 2013 over several spatial domains. In 2013 LIS detected 52.0% of the discharges ENTLN reported within the LIS field of view globally and 53.2% near North America. Conversely, ENTLN detected 5.9% of the pulses detected by LIS globally and 26.9% near North America in 2013. Using these results in the Bayesian-based methodology outlined, the study finds that LIS detected 80.1% of discharges near North America in 2013, while ENTLN detected 40.1%.

scholarly journals Investigation of Thundercloud Features in Different Regions

2021 ◽  
Vol 13 (16) ◽  
pp. 3216
Author(s):  
Andrei Sin’kevich ◽  
Bruce Boe ◽  
Sunil Pawar ◽  
Jing Yang ◽  
Ali Abshaev ◽  
...  
Keyword(s):  
Precipitation Intensity ◽  
Statistical Characteristics ◽  
Lightning Strike ◽  
Detection Systems ◽  
Weather Radars ◽  
Cloud Characteristics ◽  
Lightning Detection ◽  
The World ◽  
Regions Of Russia

A comparison of thundercloud characteristics in different regions of the world was conducted. The clouds studied developed in India, China and in two regions of Russia. Several field projects were discussed. Cloud characteristics were measured by weather radars, the SEVERI instrument installed on board of the Meteosat satellite, and lightning detection systems. The statistical characteristics of the clouds were tabulated from radar scans and correlated with lightning observations. Thunderclouds in India differ significantly from those observed in other regions. The relationships among lightning strike frequency, supercooled cloud volume, and precipitation intensity were analyzed. In most cases, high correlation was observed between lightning strike frequency and supercooled volume.

scholarly journals Lightning Data Analysis of the CMA Network in China

2017 ◽  
Author(s):  
Feng Li ◽  
Lei Wu ◽  
Yan Li
Keyword(s):  
Yangtze River ◽  
Central China ◽  
Average Intensity ◽  
Detection Systems ◽  
The North ◽  
South Central ◽  
Localization Algorithms ◽  
Lightning Detection ◽  
River Region ◽  
Statistical Results

Abstract. Based on analysis and evaluation of the 2009 to 2013 national lightning monitoring data, the average lightning detection station distance is approximately 170 kilometers in China, and the average operational availability (AO) exceeds 90 %. Lightning detection systems use a hybrid location method of direction finding (DF) and the time difference of arrival (TOA). The stations use four localization algorithms, including two-station mixing, three-station mixing, four-station mixing and two-station amplitude. Among them, the four-station method has the highest positioning accuracy, i.e., close to 50 %. The statistical results show that lightning occurrences in China have increased, especially negative cloud-to-ground (−CG) flashes because positive cloud-to-ground (+CG) flashes account for only 5.1 % of the total. In china, most of lightning currents range are in the −60 ~ +60 kA, Lightning current between −10 ~ +10 kA only accounted for small proportion of 0.6 %.The average intensity of positive flashes is 64.2 kA, the average intensity of negative flashes is −40.28 kA. The average +CG intensity is higher than that of −CG flashes, which is consistent with statistical results of other Lightning detection network. Lightning frequency has obvious regional differences across the country; the high density lightning area is mainly distributed in south-central China, the south-central Yangtze River region and the eastern part of southwestern China. Seasonal variation in lightning activity is well defined, with few lightning occurrences in winter and a gradual but significant increase from spring to autumn in the middle and lower reaches of the Yangtze River to the north, south and southwest. The ratio of positive to negative flashes is highest in winter.

scholarly journals Exploring Lightning Jump Characteristics

2015 ◽  
Vol 30 (1) ◽  
pp. 23-37 ◽  
Author(s):  
T. Chronis ◽  
Lawrence D. Carey ◽  
Christopher J. Schultz ◽  
Elise V. Schultz ◽  
Kristin M. Calhoun ◽  
...  
Keyword(s):  
Lightning Flash ◽  
Autocorrelation Functions ◽  
Tracking Method ◽  
Flash Rate ◽  
Detection Systems ◽  
Storm Tracking ◽  
Lightning Detection ◽  
Random Behavior ◽  
Temporal Occurrence ◽  
Total Lightning

Abstract This study is concerned with the characteristics of storms exhibiting an abrupt temporal increase in the total lightning flash rate [i.e., lightning jump (LJ)]. An automated storm tracking method is used to identify storm “clusters” and total lightning activity from three different lightning detection systems over Oklahoma, northern Alabama, and Washington, D.C. On average and for different employed thresholds, the clusters that encompass at least one LJ (LJ1) last longer and relate to higher maximum expected size of hail, vertical integrated liquid, and lightning flash rates (area normalized) than do the clusters without an LJ (LJ0). The respective mean radar-derived and lightning values for LJ1 (LJ0) clusters are 80 min (35 min), 14 mm (8 mm), 25 kg m−2 (18 kg m−2), and 0.05 flash min−1 km−2 (0.01 flash min−1 km−2). Furthermore, the LJ1 clusters are also characterized by slower-decaying autocorrelation functions, a result that implies a less “random” behavior in the temporal flash rate evolution. In addition, the temporal occurrence of the last LJ provides an estimate of the time remaining to the storm’s dissipation. Depending on the LJ strength (i.e., varying thresholds), these values typically range between 20 and 60 min, with stronger jumps indicating more time until storm decay. This study’s results support the hypothesis that the LJ is a proxy for the storm’s kinematic and microphysical state rather than a coincidental value.

The Potentials of Scanning Microscopy

1968 ◽  
Vol 26 ◽  
pp. 352-353
Author(s):  
A. V. Crewe
Keyword(s):  
Salient Feature ◽  
Secondary Emission ◽  
Resolving Power ◽  
X Rays ◽  
Scanning Microscope ◽  
Forming Process ◽  
Additional Tool ◽  
Detection Systems ◽  
Conventional Microscope ◽  
Present Information

If the resolving power of a scanning electron microscope can be improved until it is comparable to that of a conventional microscope, it would serve as a valuable additional tool in many investigations.The salient feature of scanning microscopes is that the image-forming process takes place before the electrons strike the specimen. This means that several different detection systems can be employed in order to present information about the specimen. In our own particular work we have concentrated on the use of energy loss information in the beam which is transmitted through the specimen, but there are also numerous other possibilities (such as secondary emission, generation of X-rays, and cathode luminescence).Another difference between the pictures one would obtain from the scanning microscope and those obtained from a conventional microscope is that the diffraction phenomena are totally different. The only diffraction phenomena which would be seen in the scanning microscope are those which exist in the beam itself, and not those produced by the specimen.

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