Combined TOA/MDF Lightning Location Using Three Globally Distant Sites
Abstract
Lightning discharges generate electromagnetic pulses, known as sferics, that propagate through the waveguide formed by the earth and the ionosphere. The energy in the VLF band of the sferic can propagate over great distances ( ∼10,000 km) with low loss (3 dB/Mm) and can therefore be detected far from the source lightning location. Using sferic measurements from VLF receivers located at three globally separated sites (Palmer Station, Antarctica; Upland, Indiana; Sde Boker, Israel) the locations of individual lightning discharges are triangulated. Both time of arrival (TOA) and magnetic direction finding (MDF) data are used in the location algorithm. The very large distances between receiver sites and a high global sferic rate ( ∼100 per second) create space-time complications in the correlation of data between sites causing ambiguities in the pairing of sferics detected at one site to their corresponding sferics detected at the other two sites. These complications sometimes result in the detection of ``ghost'' lightning discharges which occurs when physically inconsistent (not originating from the same lightning discharge) yet statistically consistent (acceptable arrival times and azimuths) sferics are used in the location algorithm. Both ``ghost'' event reduction and location accuracy for three verses two station location are discussed. Selected results are shown from August 2002.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2003
- Bibcode:
- 2003AGUFMAE32A0161W
- Keywords:
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- 3324 Lightning;
- 3360 Remote sensing;
- 3394 Instruments and techniques