Relationship Between Laboratory Simulated Multicomponent Waveforms of the Lightning Current Pulse and Discharge Channel Light Intensity

Three categories of multi-component waveforms of lightning current, composed of three simulated return-stroke pulses and fifteen simulated M-component pulses along with the underlying background current, are generated by the ladder network formed by series connected inductor-and-capacitor elements. Two types of photodetectors, namely, a redlight sensitive one with a detection wavelength range of $200 \sim 1000$ nm peaking at 600 nm, and a near-infrared sensitive one with a detection wavelength range of $400 \sim 1000$ nm peaking at 800 nm, are used to record the luminosity of the discharge gap channel. Parameter correlations are analyzed between the simulated lightning multi-component current and the corresponding channel luminosity. Results show that the peak luminosity is linearly correlated with the peak current, and that there is also a linear relationship between the luminosity 10-90% rise time and current 10-90% rise time. Correspondingly, the resulting luminosity-time integral is linearly related to the current charge transfer. An important implication of this result is that the channel optical observation may well be suitable for the inversion of lightning current transfer charge. In general, however, compared to that from the red-sensitive photodetector, the luminosity waveform from the near-infrared sensitive photodetector is observed to better match the evolution trend of current, and this fact implies that it might allow for a more accurate estimation of the current transfer charge.