Remote monitoring of mineral spills using LIDAR techniques

Summary form only given. Express-monitoring of mineral oil spilled into water is one of the most important issues in environmental protection. Remote diagnostics of mineral oil on water surface necessarily includes fast mapping of the spill, oil type recognition, and estimation of thickness of oil spilled on water surface. Since very thin oil films spreading on water surface affect the character of aquatic and atmospheric processes, it becomes important to measure film thickness with micrometer accuracy. Nowadays, the only sensor which has the ability to positively identify and quantify oil films is the laser fluorosensor. Currently LIDAR techniques for oil spill monitoring are based on detection of laser induced oil fluorescence and backscattered water Raman signal. The technique of water Raman suppression by an oil spill is used for oil film thickness measurement and evaluation of the total oil volume spread on water surface. This work describes spectral properties of mineral oils (ranging from sub-micrometer layer on water surface up to optically thick layer) excited by laser radiation under controlled laboratory conditions. Three types of LIDAR systems operating at wavelengths of 308, 337 and 355 nm were tested experimentally. The measurements were performed for several crude and refined mineral oils as pure substances and spilled into a large water container.