Invisible Border Monitoring System Uses Fiber Optic Cables for Detection

• By Cindy Horbrook
• May 02, 2011

With the state of Arizona appearing in the news somewhat regularly for its numerous attempts at border security legislation, it’s not surprising that an invisible monitoring system is being developed and tested within the state.

The system, known as Helios, consists of laser pulses transmitted through fiber optic cables buried in the ground that respond to movements on the surface above. A detector at one or both ends of the cable analyzes these responses.

The system is more accurately described as a “distributed acoustic sensor” and is made by British company Fotech Solutions. Zonge International, a Tuscon-based geophysical engineering company, brought the technology to the states and installed a test system in the Southern Arizona desert late last year. Scott Urquhart, Zonge president, said there are a few things that make Helios a unique border monitoring system.

“First, it’s completely out of sight, so the visual impact is zero. It’s also hard to interrupt because you can’t just go shoot it or something,” he said. “It’s actually quite inexpensive. It’s just traditional fiber optic cable, so the primary cost is actually just in digging the ditch.”

The University of Arizona’s Lowell Institute for Mineral Resources and National Center for Border Security and Immigration led the evaluation of the system.

“The fact that it’s distributed sensing makes it interesting and extremely useful,” said Moe Momayez, associate professor in the department of mining and geological engineering at the University of Arizona. “You can select how closely you want to monitor a stretch of land, for example. Once you set up the system and you start monitoring, there is a huge amount of data coming in. The system can be set up to monitor every meter along the fiber in real-time, and that’s probably one of the reasons (the Department of Homeland Security) would be interested because you can locate these border crossers in real-time.”

The system is sensitive enough to detect a dog and can discriminate between people, horses and trucks. It can be set to avoid being triggered by small animals, and can also tell if people are running or walking or digging, and in which direction.

“This type of distributing sensing device could be used as an early warning system for border security to tell them that there are border crossers approaching a certain location or a certain sector,” Momayez said.

The system is designed to be a component of border security and work in conjunction with existing technologies.

“From my understanding the border crossers or traffickers, they move in groups of two or three or five from different locations and then they congregate at a specific point. Border security…they want to know so they can bring their people and other technologies to that congregation point,” he said.

The system is not without some drawbacks in its current state, with the lack of an automated discrimination or classification capability described as a one downside. This means a human has to sit and monitor the system to distinguish between people, dogs, vehicles or large animals crossing the fiber.

“Fotech has told us that they are working on it, so the new version should have event detection and pattern recognition capability,” Momayez said.

Another potential problem is that someone could dig down and cut the cable. However, the issue is very preventable, Urquhart explained.

“You can see the guy starting to dig for your cable. You have an opportunity to respond to that,” he said. “The other thing is the Helios system, if you had lasers on each end, even if they cut it, both sections are alive. It’s not like an electrical wire if you cut it, it’s dead. It would still basically be working, even if there was a hole in the middle. It’s difficult to completely blind it.”

The Helios system is not new technology and is already used to monitor large engineering works such as dams, pipelines, bridges, and highways for cracks or seismic damage. It has also been used along military bases and prisons as a stand-alone system.

As far as a border security application, the University of Arizona has recommended deployment of the system over much longer stretch of land, preferably where the border patrol operates. At this time, the system is currently in a holding pattern, Urquhart said, as Zonge is seeking additional funding to do a larger experiment.

Photo: Pete Brown/UA College of Engineering