Meeting the Iran tunnel challenge

Danger Room:

...

Pentagon mad science division Darpa has an array of research projects devoted to Underground Facility Detection & Characterization. According to the program’s website, the agency’s Strategic Technologies Office is:

investing in sensor technologies that find, characterize and identify facility function, pace of activity, and activities in conjunction with their pre- and post-attack status. STO is also investigating non-nuclear earth-penetrating systems for the defeat of hard and deeply buried targets.

Seeing through solid rock might sound like a tall order, but Darpa thrives on challenge. One project is called Airborne Tomography using Active Electromagnetics, which builds on technology originally developed by the geophysical exploration industry. The ground is illuminated with electromagnetic energy — typically extremely low frequency — and the distortions on the return show the presence of underground facilities and tunnels. Some years ago, military-backed scientists at Alaska’s High Frequency Active Auroral Research Program (HAARP) were able to map out tunnels at depths of a hundred feet or greater. Papadopoulos, for example, says he wants to do another round of subterranean surveillance experiments. “Personally, I believe it can reach 1,000 kilometers. It [currently] can’t reach Iran, if that’s your question,” one of those researchers, Dennis Papadopoulos told Danger Room. “But if I put HAARP on a ship, or on an oil platform, who knows?”

Gravity Anomaly for Tunnel Exposure is even more sophisticated, using nothing more than variations in the local gravitational field caused by underground spaces. Extremely sensitive gravity gradiometers measure the difference in pull to map out underground voids. Darpa has already reached the stage of integrating the gravity gradiometer and signal processing payloads and mounting them in an unmanned aircraft, and have been “verifying performance in relevant geologic environments.”

Darpa is not neglecting the traditional methods of surveying underground structures, and there is a parallel Seismic and Acoustic Vibration Imaging effort. This might use untended ground sensors dropped from aircraft, or it might be something more advanced — Darpa’s website describes a mobile system using “an integrated, laser vibrometry system to detect seismic wave anomalies.” This might be another airborne sensor, though it might still need to drop something to produce shockwaves to create the seismic and acoustic vibration to be detected.

Darpa clearly believe that it is possible to locate and “characterize” underground facilities — this can mean everything from looking at what sort of vehicles come and go, to monitoring communications traffic or atmospheric sampling for traces of tell-tale nuclear material. It is hardly a surprise that Iran has complained of U.S. drone intrusions in recent years. Some observers suspect that the Air Force’s newest stealth spy drone in Afghanistan, the RQ-170 “Beast of Kandahar” may be sneaking over the border.

If detected, can such targets be attacked? The MOP may be capable of smashing through a lot of rock, but there are smarter approaches. The U.S. Air Force has developed skip-bombing techniques with bunker busters so that they arrive horizontally and can be aimed precisely at entrance doors. They may not destroy the entire facility, but if all the entrances are wrecked, then nothing can go in or out.

...

MOP stands for Massive Ordinance Penetrator. They are very powerful non nuclear bombs. How much of this is real and how much of it is intended to frighten the Iranians into doing a deal? I would not bet against these guys.

I do think it is a mistake to focus all of our attention on the nukes. It makes sense to destroy Iran's ability to make war in order to thwart the kind of retaliation Iran is threatening. It would take a few weeks of sustained bombing of which the nuclear sites would be a part in order to destroy much of their war making ability.