Publications

Debate on the introduction of a Directive within the European Union addressing ship-source pollution and the introduction of sanctions, including criminal sanctions, for pollution offences has brought into focus the need to understand the role of satellite surveillance in the monitoring and enforcement of illicit oil discharges from shipping, particularly the forensic analysis of Synthetic Aperture Radar (SAR) imagery.To date, the most effective methodology for near real time analysis of SAR imagery for slick detection involves the visual scrutiny of imagery by a trained analyst. Each analyst proceeds by using a set of loosely defined criteria to identify artifacts on the imagery that may be genuine oil spills. PT BMT Asia Pacific (BMT), in conjunction with MDA Geospatial Services (MDA), has over the last two years been operating a routine oil spill detection service for the West Java Sea and the Thousand Islands in Indonesia. The service has collated a database of over 220 images, which have been used as a knowledge base from which to develop a standard approach to the forensic analysis of SAR imagery in relation to oil spill.The standard approach addresses the significant characteristics of the appearance of oil in a marine SAR image. Current efforts are directed at reducing the subjectivity in interpretation of the image and the ability to assign a level of confidence to the decision that an artifact on an image is a genuine oil spill. This is being done through identifying quantitative inputs (such as wind speed) and more clearly defining ranges for qualitative inputs (such as contextual measures) through the Human- Machine Interface (HMI). The end result is a series of inputs that result in an automated confidence code for each candidate oil slick. The paper presents the concept of the Detection Triangle upon which the method of developing a confidence code is derived. Subjectivity is reduced significantly as variation in analysts inputs, which arise through decisions taken during the interpretation process are reduced.Keywords: Ship Source Pollution, Environment Security, Satellite Oil Spill Detection, Synthetic Aperture Radar, Information Systems, Environmental Decision Analysis and Knowledge Management.