Wireless sensor node for real-time thickness measurement and localization of oil spills

Marine pollution by oil spills is a devastating environmental hazard, requiring a low-cost efficient system for detection, real-time thickness measurement and localization of oil. Such a system is necessary to guide and speed-up the clean-up process. Knowing that none of the previous detection methods has managed to fully meet these requirements, it is necessary to devise a new technique to assist in management of oil spills. This paper presents a sensor device, capable of sensing, processing and transmitting information about an oil spill (location and thickness). The paper discusses two new methodologies of detection, which are based on the difference in absorbance spectral signatures and electric conductivity properties of oil and water. Measuring the resistance values of an array of photodiodes and the current intensities between an array of conducting strips both allow us to estimate the thickness of the oil. The experimental results, presented in this paper, illustrate the effectiveness of the proposed method under different lighting conditions. With the capability of forming a wireless ad-hoc sensor network, these proposed devices will produce together a real-time map of the current state of an oil spill, including its thickness level at different locations.