A growing safety concern for pilots and aircraft passengers is laser strikes, or the aiming of high-power laser pointers at aircraft. To address the present lack of effective laser strike mitigation systems, the Laser Technology and Applications and Air Traffic Control Systems Groups at MIT Lincoln Laboratory have teamed up to develop the Laser Aircraft Strike Suppression Optical System (LASSOS). LASSOS is a ground-based sensor system that can accurately identify the probable location of a laser perpetrator.
The system works by capturing side-scattered laser light and tracing it back to the perpetrator's location. When a laser is shone into the sky, a small fraction of the light is scattered by air molecules and aerosols, forming a residual streak in the laser's path. Two or more high-sensitivity, low-noise charge-coupled device (CCD) cameras image the scattered light from different vantage points, providing the geometric diversity needed to digitally reconstruct the laser streak in three dimensions. The geographic coordinates of the laser's origin are calculated by tracing the laser streak down to a topographically accurate model of the Earth's surface.
A feature of LASSOS that makes it particularly effective is its integration with Google Earth. As soon as a laser is detected by the cameras, a digital reconstruction of the streak appears on a Google Earth map in real-time. This image summarizes the detection event, depicting the laser's point-of-origin and most probable path through the night sky. Within 30 seconds of the image being captured, LASSOS provides nearby members of law enforcement with the perpetrator's GPS coordinates, nearest address, and the time of the incident. This information allows officers to rapidly intervene.
The system prototype has already demonstrated its speed and accuracy in several tests. For one test trial, LASSOS's geolocation ability was tested at a distance of nine nautical miles to simulate the typical length of a final approach path when an aircraft is most vulnerable to lasing. One sensor was placed on top of the B Building at Lincoln Laboratory and another on the Flight Test Facility at Hanscom Air Force Base. Testers shone high-power laser beams (of the type used during lasing events) from a baseball field nine nautical miles away in Tewksbury, Massachusetts, and were geolocated by LASSOS in less than 30 seconds. The system was so accurate that it could distinguish whether the laser beams came from first, second, or third base on the field.