Lightning Interferometer via VHF Emission

The Lightning Interferometer via VHF Emission (LIVE) is the next iteration of flash continuous, broadband, interferometric lightning mapping systems. LIVE consists of 4 or more flat plate VHF antennas, sensitive to the 30-80 MHz bandwidth. These data are recorded at a rate of 180 MHz, and then processed in real-time to produce detailed maps of a lightning flash. Each real-time map locates between 5,000-50,000 lightning VHF sources, and does so in a matter of seconds. These maps can be converted into 2-dimensional, x-y plan locations allowing the location of nearby lightning to be estimated using a single sensing location. LIVE is also fully capable of retaining the raw data for each flash, in which case the data can be reprocessed at much higher quality to produce maps of lightning with stunning detail. To test the system, LIVE was deployed in Kanazawa along the northern coast of Japan to observe Japanese winter lightning, and in Kaizuka near Osaka Bay to observe Japanese summer lightning. Presented are preliminary observations from both regions. Japanese summer lightning initiates at typical altitudes (5-10 km) and produces relatively normal looking lightning flashes. In contrast, Japanese winter lightning happens at very low altitudes, initiating as low as 1 km above the ground, and tends to have extremely active negative breakdown regions. This makes winter lightning in particular difficult to locate using interferometer. Still, for nearby flashes, LIVE performs very well even for Japanese winter lightning.