Oil pollution monitoring by SAR imagery

Russia is the first world gas producer and the second for oil. Its reserves of hydrocarbons are primarily located in the Russian North where permafrost is often present. Large oil spills occur in this area. The pipelines are subject to corrosion and cryogenic processes. The risk of rupture increases consequently. The oil spill monitoring is limited by the vastness and the frequent inaccessibility of the pipeline network and therefore, requires remotely sensed data. The ability of ERS Synthetic Aperture Radar (SAR) data in the detection of Usinsk’s oil spill, which occurred in 1994, is carried out in this study Moreover, some disturbing factors such as the characteristics of the sensor, the sensor look direction, the topography and the speckle, make difficult the SAR data processing. In fact, the determination of the features of the target depends on the knowledge of these disturbing effects. Examples of such features presented here are interpreted based on the regional and temporal context of the SAR imagery as well as the morphology and temporal persistence of the features. Thus, the digital image processing techniques included radar backscatter calibration, speckle filtering, edge detection filtering, brightness value (dB) analysis and oil spill shape analysis are used to enhance the spillage area in the ERS imagery over the Usinsk’s area. The method developed here using 3 SAR images is discussed especially in terms of limits and possible uses as a routine.