In recent Israel-Palestine Conflict, Israel had carried out massive ground offensive to wipe out a vast network of tunnels built by Hamas. Israel sees these being built for infiltrating its territory, smuggle large amounts of firearms and other sabotage materials into the Gaza Strip. Many bemoan the fact, that such a large number of tunnels dug by Hamas from Gaza into Israel have gone undetected for so long.
The tunnel threat is a serious and growing concern to U.S and Mexico, as they enable human trafficking and smuggling of drugs and weapons across the border. It seems tunnel warfare is becoming a global concern as it is also common in other parts of the world such as Iraq, Afghanistan and Syria where rebels use them in combating Assad’s military forces.
In between 2001 and 2016, India has discovered at least eight tunnels originating from across the border along Pakistan, at an average of one every two years. And, only one of these is suspected to have been dug for drug running, while the others are linked to possible or successful infiltrations.
Many defense companies including Lockheed Martin and Raytheon, are developing technologies for detecting tunnels. U.S. government is earmarking $120 million over the next three years and partnering with Israel to help develop a new tunnel detector. The goal, U.S. Defense Department spokesman Christopher Sherwood told Foreign Policy, “is to establish anti-tunnel capabilities to detect, map, and neutralize underground tunnels that threaten the U.S. or Israel…”
The Israeli government, has been developing such a system for at least the past five years. Codenamed project “Hourglass,” Israel has already invested the U.S. dollar equivalent of more than $60 million in the system, involving help from more than 100 technologies, defense, and engineering companies. Remote controlled robots help agents explore tunnels that are too risky for humans to enter.
Part of the problem in detecting tunnels, say experts like Paul Bauman, a Canadian geophysicist, is the ground itself. Finding what is under the surface is not as simple as shooting radar or electromagnetic waves into the ground, he said. With underground cracks, water tables, tree roots and caves, it is hard to tell what is and is not a tunnel, he said. Mr. Bauman, who has worked with the Israel Defense Forces in their efforts to find tunnels, said most of the devices used for tunnel detection were developed for industries to find oil or mineral deposits, not drug tunnels.
Carey M. Rappaport, a professor of electrical and computer engineering at Northeastern University in Boston, said the depth of many tunnels also posed a technological challenge. Some can be as deep as 90 feet, beyond the reach of most groundradar devices and sensors. “Soil is very good at keeping secrets,” said Mr. Rappaport, who has also worked with the United States and Israeli governments on tunnel detection methods.
Recently, the Science and Technology Directorate of the Department of Homeland Security concluded that none of the current methods used to detect underground tunnels were “necessarily suited to Border Patrol agents’ operational needs.”
Around 170 tunnels have been discovered since 1990, Sixty percent of them discovered in just the last three years. Recently a drug smuggling tunnel was discovered along the California-Mexico border that set the record for the longest cross-border tunnel ever discovered in Southern California. According to the Department of Justice’s accounting, the tunnel was estimated to span 800 yards, and likely a lot longer due to its “zig-zagging” route, as Assistant U.S. Attorney Timothy Salel put it. “It is equipped with rail and ventilation systems, lights and a sophisticated large elevator leading from the tunnel into a closet inside the Tijuana residence,” he added. “It is one of the narrowest tunnels found to date, with a diameter of just three feet for most of the length of the passageway.”
An Israeli company, Magna, has proposed digging a 70-km tunnel along the Israel-Gaza border, equipped with a sensitive alert system. The system shall be able to localize attack tunnel, estimate how many people are in it, and can monitor the progress of digging. Now, Israel Hayom reports, Israel has built its own network of defense tunnels along the Gaza border, with the cooperation of the United States.
Tunnel detection technologies
Most of the existing tunnel detecting capabilities are modifications of existing equipment originally used to detect land mines or natural gas and oil deposits. More sensitive, sophisticated techniques are needed to find tunnels, which exist between those two extremes of size and depth.
Some of the technology solutions that have been found useful for tunnel detection are
The effectiveness of tunnel detection devices is directly related to the geophysical characteristics of local soil. DHS&T is in the process of collecting and compiling a database of existing derived and new geological and geophysical survey data along the border where the tunneling is most probable.
Ground penetrating Radar
Special radar mounted on a vehicle that uses pulses of appropriate frequency and ultra wideband waveforms to form an underground image. Its promising technology widely used in quality-testing roads, and to find unmarked graves, locate utility lines, trace subsurface geology, sweep for mines and search archaeological sites. However, some of its limitations of this method is that it does not work well in most mediums like clay and rarely penetrates deeper than 40 ft and produces lots of false alarms even at shallow depths leading to waste of time and money. The developers are concentrating their efforts on using much lower frequencies that can penetrate the ground much deeper, and a sophisticated new imaging technology that can display clear pictures of deep tunnels.
Seismic Sensor Network
The underground activity like digging, drilling, scraping, jack-hammering, can create the ground disturbances or vibrations that travel through the ground in the form of seismic waves and can be detected by seismic sensors like geophones buried under the ground.
Signal processing is the critical technology for extraction of data and intelligence from the signals generated by seismic sensors, identifying the type of activity like digging, walking, vehicle etc. and also the localization of activity. The intelligent algorithms can also filter out non-threatening vibrations, from construction equipment, traffic on nearby roads and underground subways, in order to minimize false alarms.
A combination of Airborne SAR (Synthetic Aperture Radar) and GPR has also been proposed for underground tunnel detection. Some of the other proposals include measuring electrical resistivity through metal electrodes, microgravity sensors and detecting muons underground brought by cosmic rays hitting the earth.
Robots in anti-tunnel campaign
IDF‘s military robot Talon 4 has been used in dangerous tunnels on the Gaza Strip border instead of soldiers to reduce risks to troops.
Manportable tunnel mapping robot
Another are lightweight, portable Carrier Robots, that would be carried by soldiers on their backs. They shall be capable of scanning areas underground for many hours, mapping entire buildings and terror tunnels. It is equipped with cameras, sensors, and a communications system capable of transmitting signals from underground. The groundbreaking technology will allow soldiers to understand the exact appearance of any structure, helping them avoid the dangers of underground or urban combat as explained by Major Lior Trablisi, the head of the IDF’s robot and technology unit.
“Robotic-laptop soldier,” will assist soldiers from the Combat Engineering Corps and infantry soldiers in underground combat. The idea of this small-scope robot is to take on dangerous missions, including patrolling and collecting information for the fighters on the ground. This will solve many of the problems soldiers are forced to face when operating underground, such as collapsing walls and lack of oxygen and lighting.
Underground Iron Dome i.a. Against Hamas’ Terror Tunnels
Western sources reported on 11th March 2016, that the new weapon, dubbed the “Underground Iron Dome,” can detect a tunnel, then send in a moving missile ton blow it up. The new weapon is not counter measure only against threat from Gaza and Lebanon but against Iran nukes too.
US intelligence sources disclosed only that new weapon is equipped with seismic sensors to detect underground vibrations and map their location before destroying them. Western experts haven been talking for years about a secret Israeli weapon capable of destroying Iran’s Fordo nuclear facility, which is buried deep inside a mountain not farn from the Shiite shrine city of Qom.
They suggested that this hypothetical weapon could be slipped through the Fordo facility’s vents, thread its way through the underground chambers and take down the illicit enrichment facility. It was discussed again three years ago, when the Israeli Air Force on 23rd Aug. 2013 blew up the Popular Palestinian Front-General Command underground facility at Al-Naama on the South Lebanese coast, 15 km south of Beirut.
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