This grainy black-and-white image may not look like much, but it's a record-breaker. A radar scan acquired by satellite and beamed back to Earth by laser, it allowed the European Space Agency (ESA) to identify ships off the coast of Brazil in less than 18 minutes -- without any satellite ground stations nearby. That may sound like a long time, but it's actually the fastest time in which a radar scan has ever been acquired, sent back to Earth, and processed in order to detect ships in otherwise blind spots of the oceans. The scan was acquired by the ESA's Sentinel-1A satellite, then beamed to Oberpfaffenhofen and Neustrelitz in Germany. The processing of the images took 13 minutes, and the analysis a further five. The laser link is the crucial part: Without that, the satellite would have had to wait up to an hour or more to beam back the data to a ground station.
The space agency calls the technique quasi-realtime, because the time scales involved in gathering, transferring and processing the data are well within the demands that are required when scouring the oceans for ships. It's thought that the technique could be used to monitor oil spills or perhaps even spot piracy.
Image by ESA