Continuous Long-Range Thunderstorm Monitoring by a VLF Receiver Network Part I: Instrumentation and Location Error Analysis
Lightning emits radio noise (sferics) over a broad region of the electromagnetic spectrum. Sferics in the Very Low Frequency (VLF) between 5 and 15 kHz propagate over thousands of kilometers in the earth-ionosphere wave-guide. An experimental network of five ground-based radio receivers, was situate...
Main Authors: | , , , |
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Other Authors: | |
Format: | Text |
Language: | English |
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Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.199.3476 http://sifnos.engr.uconn.edu/~manos/mwa02.pdf |
Summary: | Lightning emits radio noise (sferics) over a broad region of the electromagnetic spectrum. Sferics in the Very Low Frequency (VLF) between 5 and 15 kHz propagate over thousands of kilometers in the earth-ionosphere wave-guide. An experimental network of five ground-based radio receivers, was situated along the US east coast and Puerto Rico. That network measured sferics between July 1997 and February 1998. In this study, sferics distributions from this experimental network are compared to lightning data form the US National Lightning Detector Network (NLDN) and the Lightning Imaging Sensor (LIS) onboard the TRMM satellite. An analysis which neglected non-linear propagation effects on pulse shapes produced location errors up to 100 kilometers due to uncertainties in signal processing, phase velocity modeling, and radio receivers ’ spatial configuration effects. After applying statistical corrections, North Atlantic Ocean and northwest South America regions location errors were reduced to less than 50 km. Expected errors derived from Monte Carlo simulation for this experimental network agreed with the errors retrieved from independent measurements with some moderate disagreement over the west coast of US. A location error correction scheme is developed, which combines theoretical and experimental models along with satellite infrared observations. Significant location error reduction is demonstrated, with corrected errors varying from less than 20 km to less than 60 km in the eastern and western part of US, respectively. ii |
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