Transient Radiative Transfer Model for Improved Remote Sensing of Lightning through Clouds
Past Sponsor: Florida Space Grant Consortium
The objective of this research is to determine the information content of lightning optical emissions through cloud multiple scattering media for atmospheric remote sensing applications using transient radiative transport models. The spatial and temporal variability of the optical intensity is examined to determine the feasibility of extracting detailed information about the cloud medium (which includes microphysical state, optical depth, particle size, number density of scatters, extinction coefficient, asymmetry factor of the scattering phase function) and/or the lightning source itself (which includes radiant amplitude, channel length/orientation, tortuousity pattern). The measured optical signals are functions of the medium properties, and the characteristics of the optical wave form can be used to infer these properties. In order to validate and compare the results of the optical emissions obtained by solving the transient radiative transport, it is critical to perform carefully designed laboratory experiments. A short laser pulse source is incident in a mixing chamber, which simulates a cloud medium. Laboratory experiments are extremely crucial because they can be carefully tailored to examine desired parameters, and experimental conditions can be controlled and characterized to ensure they match that of the numerical models. This study will pave the way for developing alternative lightning detection schemes such as by using sounding rockets launched from the KSC/45 Weather Squadron, USAF launch pads.
Banerjee, A., and Mitra, K., “ Experimental Simulation of Lightning Optical Emissions in Clouds,” Journal of Physics D: Applied Physics, Vol. 39, pp. 575-583 (2006).
Ogale, A., Banerjee, A., Subramanian, C.S., and Mitra, K., “Experimental Simulation of Remote Sensing of Lightning through Clouds Using Short Pulse Lasers,” 9th SPIE International Symposium on Remote Sensing, Crete (Greece), Paper No. 4882-01 (2002).