Signals from the ocean indeed! Think "warfare". (Score 1)

Let's see, two military uses for this technology: "...BlackJack can pinpoint the position of its host satellite continuously with an accuracy of 2 to 3 centimeters..." 1. Satellite warfare would be one. That whole "Star Wars" deal the American government is excited about (and committed to). "The BlackJacks are also equipped with small down-looking antennas to attempt to receive GPS signals that reflect off the oceans." 2. Sounds like a great way to pin-point the location of "enemy" submarines too. Get your "launch codes" and get tagged by a space-ear. http://www.jpl.nasa.gov/releases/2000/blackjackgps .html