Today's ships are equipped with radar systems that let them identify other ships from a distance, and while that works well enough for collision avoidance, those systems aren't the greatest at detecting small watercraft ... such as the low-slung skiffs often used by pirates. That's where WatchStander comes in. It's a radar system that's designed to pick out such boats, and then deter their crews before they can attack.
WatchStander uses shorter radio wavelengths than a ship's standard radar system, which is what allows it to detect smaller watercraft that are up to 2 miles (3.2 km) away. Using artificial intelligence software developed at Penn State University's Applied Research Laboratory, it then tracks those boats and watches to see if any of them exhibit "antagonistic behavior" – this could include approaching the ship at high speed, on an intercept course.
If any of them do so, the ship's crew will be alerted via visual and audible alarms, plus WatchStander's high-intensity spotlight will be shone at that boat. The light serves to both disorient the possible pirates, and to let them know that they've been spotted, and have therefore lost the element of surprise.
Should the vessel continue to approach, the spotlight will go into a more disruptive strobing mode. If things progress further, other possible non-lethal countermeasures that could be used include sonic and laser deterrents, or pepper spray projectiles. The integrated video system also records the entire encounter, for future reference.
The system is autonomous, with the ship's WatchStander unit(s) automatically panning and tilting to stay trained on the suspect vessels. This means that the ship's crew can take refuge if wanted. They can override the system if it becomes clear to them that a boat doesn't pose a threat, or they can likewise declare a vessel to be a threat, if they realize it is one before the system does.
Source: WatchStander via New Scientist