Lidar Sensing of Plume Dispersion: Analysis Methods and Product Quality for Light-Scattering Tracer Particles

Abstract

Analysis procedures are described for retrieving accurate plume information from lidar data on light-scattering particles during atmospheric dispersion experiments. Interactive computer graphics aided in the solution of the lidar equation for each pulse to infer the distribution of the oil fog tracer. A two-component method was applied to adjust the measured backscatter for the effects of attenuation by the ambient haze and by the plume. Contaminating signals, especially from the surface of the hilly terrain, were also removed. Optically dense plumes made it difficult to accurately retrieve concentrations on the side of the plume opposite the lidar. Data were converted to coordinate systems convenient for dispersion analysis and archived on printed tables, graphs, and digital magnetic tape. A case study from the Tracy Power Plant experiment illustrates the procedures for data acquisition and analysis, including both strengths and limitations of the lidar method. Concentrations of the lidar-observed oil fog during the CONDORS (CONvective Diffusion Observed by Remote Sensors) experiment agreed well with a simultaneous release of SF6. The two types of tracers serve complementary roles in describing the behavior of the plume.