VHF lightning sensors and field measurements: An application to airport weather monitoring

This work develops tools for evaluating VHF lightning location sensors. Such sensors may be used to predict convective weather phenomena that are hazardous to aviation, particularly microbursts. VHF or UHF sensors are prime candidates to collect the desired cloud-to-ground and intracloud location data because these sensors can locate intracloud flashes better than existing wide area sensors. Local area VHF lightning location systems are evaluated with respect to their suitability in providing accurate three-dimensional source position. The systems considered use time difference of arrival (TDOA) and interferometric measuring techniques. A hybrid system which use both techniques is also considered.; Wideband (6 MHz) VHF lightning radiation data was obtained at an Orlando, Florida site. Wideband data are presented in terms of a "duty cycle" which is defined in this work. Duty cycle should be a useful tool in evaluating detection efficiency. The study suggests the modelling of VHF radiation as a log normal rather than Gaussian random process.; An algorithm is described which separates impulsive radiation from the more continuous radiation that occurs in lightning flashes. This algorithm can be used to provide real-time impulsive lightning data to TDOA systems. The algorithm can also be used as a tool to understand the statistical nature of lightning.; A cost-effective, five-site TDOA system with a site spacing of 1 km is presented and evaluated for possible airport deployment.