Comparison study of Lightning VHF interferometric and LF time-of-arival maps
Abstract
Lightning discharges radiate broad band frequency electromagnetic waves from ULF to UHF. Using sensors which detect this radiation is an effective technique to detect lightning flashes, even if they are in a cloud. If multiple sensors are present, a lightning flash can be located using various techniques. At low frequencies, the power radiated by lightning is very high, but because the wavelengths are long, the location resolution is somewhat low. At very high frequencies, the wavelengths are much shorter allowing for much better location resolution, but the power radiation is also much lower, making it more difficult to detect. The VHF band is a good compromise between good location resolution, and good detection efficiency. One technique to locate VHF signals from lightning is interferometry. Using this technique, the signals arriving at three or more VHF broadband antennas are coherently combined to produce an image of the lightning flash. The current generation broadband lightning interferometer being developed in Japan by RAIRAN and the University of Osaka called Lightning Interferometer via VHF Emission (LIVE). Currently, LIVE is installed in Kaizuka, a city to the south of Osaka, near Osaka Bay to observe Japanese summer lightning. In the current study, we are comparing the high detail, 2-dimensional lightning maps produced by LIVE to the lower detail, 3-dimensional maps produced by a low frequency time-of-arrival system called the Broadband Observation network for Lightning and Thunderstorms (BOLT). In order to better compare the data, a new GPS timing device is being developed for LIVE to allow high absolute timing accuracy without sacrificing one of the 4 high speed digitizer channels. The objectives of the study are to better understand Japanese summer lightning, and to prepare for a future campaign as part of the GLM validation study.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFMAE13A0404K
- Keywords:
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- 3304 Atmospheric electricity;
- ATMOSPHERIC PROCESSESDE: 3314 Convective processes;
- ATMOSPHERIC PROCESSESDE: 3324 Lightning;
- ATMOSPHERIC PROCESSES