Tag Archives: DARPA GPS

GPS System under the Sea: DARPA POSYDON

image from wikipedia

The objective of the POSYDON program is to develop an undersea system that provides omnipresent, robust positioning. DARPA envisions that the POSYDON program will distribute a small number of acoustic sources, analogous to GPS satellites, around an ocean basin.  By measuring the absolute range to multiple source signals, an undersea platform can obtain continuous, accurate positioning without surfacing for a GPS fix.

DARPA program  April 14, 2015

See also DARPA Hydra

Replacing GPS: the C-SCAN of DARPA

C-SCAN-W

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 (NYSE: LMT ) 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

GPS Jammers and Spoofers

attaching GPS kit to bomb. Image from wikipedia

GPS jammers are cheap: a driver can buy a dashboard model for about £50 ($78). They are a growing menace. The bubbles of electromagnetic noise they create interfere with legitimate GPS users. They can disrupt civil aviation and kill mobile-phone signals, too. In America their sale and use is banned. In Britain they are illegal for civilians to use deliberately, but not, yet, to buy: Ofcom, a regulator, is mulling a ban. In recent years Australian officials have destroyed hundreds of jammers.

In the right (or wrong) hands, they are potential weapons. Britain’s armed services test the devices in the Brecon Beacons in Wales, a military training area. North Korea uses big lorry-mounted versions to block GPS signals in South Korea. Starting with a four-day burst in August 2010, the attacks, which come from three positions inside the North, have lengthened. In early 2012 they ran for 16 days, causing 1,016 aircraft and 254 ships to report disruption…Criminals or terrorists could knock out GPS for an entire city or shipping lane anywhere in a flash. Even without North Korean-sized contraptions, the jamming can be substantial. Suitcase-sized devices on sale on the internet claim a range of 300-1,000 metres.

Malfunctioning satellites and natural interference from solar activity have hit GPS signals and sent ships off course. David Last, a navigation expert, says an accidental power cut, perhaps caused by a jammer taken on board a car ferry, could cause a shipwreck. Generating a false signal—spoofing—is another threat. In December 2011 Iran said it had spoofed an American drone before capturing it (most experts dismiss the claim). So far effective spoofing seems confined to laboratories, but Mr Last says some governments are already taking countermeasures.

One solution is a different means of navigation. In April South Korea announced plans for a network of 43 eLoran (enhanced long-range navigation) ground-based radio towers, based on technology first used in the second world war. It uses a far stronger signal than GPS, and should give pilots and ships’ captains a safer alternative by 2016. With Chinese and Russian help, South Korea hopes to expand coverage across the region.  Britain’s General Lighthouse Authorities (GLA) are following suit with seven new eLoran stations. Martin Bransby, an engineer with the GLA, says this will replace visual navigation as the main backup for GPS. It will be working by mid-2014, and cost less than £700,000; receivers cost £2,000 per vessel. By 2019 coverage should reach all big British ports.

America’s military-research agency DARPA has an experimental “single-chip timing and inertial measurement unit” (TIMU). When finished, according to the project’s boss, Andrei Shkel, it will use tiny gyroscopes and accelerometers to track its position without using satellites or radio towers. America’s White Sands missile range in New Mexico is installing a “Non-GPS Based Positioning System”, using ground-based antennae to provide centimetre-level positioning over 2,500 square miles. In May the Canadian government said it would splash out on anti-jam upgrades for military aircraft.

A new version of the US air force’s bunker-busting bomb, designed in part to destroy Iranian nuclear facilities, includes technology to prevent defenders from blocking its satellite-based guidance systems. MBDA, a European missile firm, is working on similar lines.

But for many users, GPS and other space-based navigation systems—which include Russia’s GLONASS, China’s partly complete Beidou, and an as-yet unfinished project by the European Union—remain indispensable and ubiquitous. They are also vulnerable. For those whose lives or livelihoods depend on knowing where they are, more resilient substitutes cannot come fast enough.

GPS jamming: Out of sight, Economist, July 27, 2013, at 51

Beyond GPS: DARPA All Source Positioning and Navigation Program

DARPA’s All Source Positioning and Navigation (ASPN) program seeks to enable low cost, robust, and seamless navigation solutions for military users on any operational platform and in any environment, with or without GPS. In particular, ASPN will develop the architectures,  abstraction methods, and navigation filtering algorithms needed for rapid integration and reconfiguration of any combination of sensors. This will enable rapid adaptation to evolving missions as well as reduction of the system integration costs and time-to-market for navigation solutions in general.

The goal of Phase 2 of ASPEN is to address the issues of optimization and real-time operation, showing capabilities beyond basic plug-and-play flexibility. Solutions must be capable of adapting to a diverse set of sensor and IMU inputs and selectively choosing the subset of measurements that produces the best possible solution, ideally mirroring the result from a tuned filter solution for that same scenario….Phase 2 solutions will need to demonstrate real-time operation in representative field (non-laboratory) environments. Although adaptability is the main goal of the ASPN program, the possibility of ASPN accuracy being substantially better than current state of art should be considered, given accommodation by ASPN of larger and more diverse sensor suites, ease of optimizing ASPN to immediate applications, and potential synergistic benefits of an open architecture.