Airports contain high levels of security and surveillance; however, other areas, such as coastal areas and harbors, remain less protected against acts of terror. These areas tend to lack radar systems to keep track of small boats, meaning terrorists could easily use this to their advantage and transport explosive devices through speedboats.
This lack of security will soon change because researchers from Fraunhofer Institute for Communication, Information Processing and Ergonomics have developed a surveillance system for these unprotected regions. It is a mobile radio passive radar technology called Passive Coherent Location (PCL) that can detect acts of terror. The technology uses radio signals emitted by cell towers to detect suspicious boats in surrounding areas and works to sense attacks on all boats, big or small.
This technology works like most other radar systems – by sending electromagnetic signals towards an object and then collecting the echo the object returns.
“Similarly, the PCL system detects boats based on reflected electromagnetic radiation from mobile networks. It is much more difficult, however, to evaluate radio signals than radar. A radar antenna transmits its own well-defined signals into a limited area. Echoes can be easily interpreted. The new sensor makes use of mobile network radio signals coming from different directions and from different cell towers. It receives a chaotic echo mix from which objects have to be carefully extracted. One challenge is that our sensor system tends to pick up the strong signals from the cell towers themselves. The signal echoes reflected off the boats on the water are considerably weaker,” Reda Zemmari, project manager at FKIE, said.
Researchers worked hard to make up for the shortcomings of this software and it can now suppress strong radio signals coming directly from cell towers. Researchers have conducted numerous tests on the technology and the system successfully tracked tiny speedboats from over four kilometers away.
This technology will protect ports and coastal communities and but it has other uses as well. Researchers are working on a new version of the technology to assist in detecting wind turbines and other harsh weather
“Tall turbine towers must be lit up at night with blinking lights to warn airplane and helicopter pilots. Unfortunately, the blinking bothers many people. Instead, wind turbines could be equipped with airplane detectors that switch the lights on only when a plane is approaching. Detectors that react to radio signals from airplanes already exist. But we need a redundant system in case these break down – and PCL technology is well suited for that task,” Zemmari added.
