DARPA Mines Nature for GPS Backup

November 8, 2015

Politico.com
by Leigh Munsil
09/18/2015 03:53PM EDT

ST. LOUIS – The Defense Advanced Projects Agency, fearing the Pentagon’s most important navigation system could be knocked out, has discovered what it believes could be one promising alternative to securely pinpoint the location of military forces without relying on relatively weak and vulnerable satellite signals.

And it’s a solution that would make Benjamin Franklin proud: harnessing lightning.

The technology, known as sferics, is the process of mining the energy put out by cloud-to-ground lightning strikes and using that data to determine an aircraft or person’s position relative to the strike. Sferics-Based Underground Geopositioning is being tested under a contract with Argon ST, a subsidiary of Boeing, and a series of tests planned for later this year and next could determine whether it could be used by military forces within the next decade, according to senior DARPA officials.

It is part of a larger, high-priority Pentagon research effort to develop a backup to the Global Positioning System that is also studying how to use modern imaging technologies to pinpoint locations with the aid of star constellations. DARPA is drawing in ideas from big defense companies and small boutique tech firms alike that could change not only the way the military navigates – but someday even average citizens driving their cars or traversing the corridors of shopping malls.

GPS, which was first developed under the auspices of DARPA and is now widely available commercially, is used by military forces for navigation as well as weapons-targeting. It has a very accurate timing signal, so it’s also used for everything from synchronizing power grids to timestamping financial transactions. It is considered the most accurate and reliable navigation system ever developed.

But its weak signal means it has serious limitations.

For one, it can’t reach into or between buildings, caves or other obstructed terrain. And large swaths of it also could be taken out by an enemy force, blocked by an average citizen with a $50 cigarette-lighter jammer or disrupted by anything from a satellite malfunction to a solar flare.

“[The GPS] signal is extremely weak, it’s about a millionth of a billionth of a watt, and hence we can’t pick it up in all the places we’d like to, such as indoors or urban canyons,” said Lin Haas, a program manager for DARPA’s Strategic Technology Office.