Oceans cover much of our planet and they are difficult to keep under surveillance, with the trafficking of people, unlicensed fishing and piracy adding to the problem. Satellites, however, can help keep the seas safe. Satellites monitor the entire planet and are an obvious component of an improved surveillance system. Satellite imagery can be used to locate and track vessels, monitor beaches and ports, and detect unlicensed fishing and illicit oil discharges. In addition, spaceborne receivers pick up identification messages transmitted by all large vessels. However, not all maritime authorities can access information from satellites at present. Read More