An Update on Oil Spill Remote Sensors

摘要

Remote-sensors for application to oil spills are assessed and recent developments given. A common sensor is an infrared camera or an IR/UV system. This sensor class can detect oil under a variety of conditions, discriminate oil from some backgrounds and has the lowest cost of any sensor. The inherent weaknesses include the inability to discriminate oil on beaches, among weeds or debris and under certain lighting conditions, oil is not detected. Furthermore, water-in-oil emulsions are sometimes not detected in the infrared. New technology has made IR technology very cheap and practical, so despite its limitations, it will be a very important tool in the future. The laser fluorosensor is a most-useful instrument because of its unique capability to identify oil on backgrounds that include water, soil, weeds, ice and snow. It is the only sensor that can positively discriminate oil on most backgrounds. Disadvantages include the large size, weight and high cost. Radar, although low in priority for purchase, offers the only potential for large area searches and foul weather remote sensing. Radar is costly, requires a dedicated aircraft, and is prone to many interferences. False targets can be as high as 95%.rnEquipment that measures relative slick thickness is still under development. Passive microwave has been studied for several years, but many commercial instruments lack sufficient spatial resolution to be practical, operational instruments. A laser-acoustic instrument, which provides the only technology to measure absolute oil thickness, is under development.rnEquipment operating in the visible spectrum, such as cameras and scanners, is useful for documentation or providing a basis for the overlay of other data. It is not useful beyond this because oil shows no spectral characteristics in the visible region. Less use is being made of visible equipment in recent years.rnSatellite-borne sensors are useful, particularly radar, however their frequency of overpass and lesser spatial resolution, make them of marginal use for spills.