Teaming up with Northrop Grumman as its primary contractor, DARPA is working today to integrate micro-electro-mechanical systems, called MEMS, and atomic inertial guidance technologies, forming a new “single inertial measurement unit” in a project designated the “Chip-Scale Combinatorial Atomic Navigator” — C-SCAN.

Translated into plain English, what C-SCAN aims to accomplish is to create a chip that performs the functions today served by orbiting GPS satellites. The chip would constantly “know” where it is in space-time, and would have this knowledge without having to ping a satellite (and maintain line-of-sight communication with a satellite) to do it… Elimination of the need to rely on satellites to determine one’s location would similarly enable the use of “GPS-like” technology for getting directions within buildings and underground — for example, in subway systems…

One of the primary vulnerabilities in today’s hi-tech, ultra-accurate weapons systems, you see, is their dependence upon GPS signals to guide them to their destinations. American “smart bombs” and guided missiles all depend greatly on GPS to know where they are, and to get where they’re going. American dominance in drone technology, similarly, depends on GPS.  Problem is, while we know this is a problem, the “bad guys” know it, too — and can sometimes hack GPS signals so as to confuse, and even hijack, American weapons systems. Case in point: in 2011, Iran boasted that it had commandeered and captured a Lockheed Martin RQ-170 Sentinel — one of our most advanced “stealth” surveillance drones — in flight over Iranian territory. The Iranians didn’t have to shoot the drone down, either. Instead, they forced it to land in Iran, and captured it intact. According to Iranian engineers, this was accomplished by first jamming communications with the Sentinel’s remote controllers, then “spoofing” GPS signals, tricking the drone into landing at what it thought was its home base in Afghanistan — but what was actually an Iranian airfield.

Drones equipped with a future C-SCAN technology would be less likely to fall victim to such a trap. While their communications might be cut off, forcing them to default to autopilot and return to base, they’d at least return to the right base, because an internal chip would tell them how to get there.

Current weapons systems often include internal gyroscopes, granted, that perform some of the functions that C-SCAN aims to perfect. But as DARPA observes, present-day gyroscopes are “bulky” equipment, “expensive,” and don’t perform with the kind of accuracy that DARPA wants to see.  The objective, therefore, is to explore cutting edge technologies to put gyroscope-like functionality on a chip, resulting in “small size, low power consumption, high resolution of motion detection and a fast start up time” — all loaded onto one small microchip….

Microchip-based guidance could be the solution the military is seeking to an oft-discussed problem with the nation’s newest generation of Mach 7 railguns, whose great range, speed, power — and cheapness — make them an attractive weapons system… if we can only figure a way to guide their projectiles accurately

Rich Smith, Why Is the U.S. Government Working Frantically to Get Rid of GPS?, Motley Fool, June 15, 2015