It may look like a piece of artwork, but this small antenna is actually powerful enough to help track ships from space. Built compact enough to fit onto a minisatellite, this antenna successfully tracked Automatic Identification System (AIS) signals emitted from commercial sea vessels during a test run abroad the International Space Station in 2010.
AIS signals continually broadcast updated identification and navigation data but the VHS system that it relies on only has a horizontal signal range of about 40 nautical miles (74 km), making earth-based tracking of open sea traffic difficult. The vertical reach of these signals is far greater, extending into space, thereby making satellite-based tracking a more efficient solution.
More:
Compact AIS antenna. European Space Agency, January 15, 2016.
Dousset, T., Sarrazin, J., Lepage, A. C., Diez, H., & RENARD, C. (2012). Compact patch antenna for automatic identification system (AIS). In International Symposium of Antenna Technology and Applied Electromagnetics (ANTEM) (pp. 1-5).
Map of global ship traffic based on AIS signals detected from orbit. Source: LuxSpace, 2016.
