JED - February 2016 - (Page 22)

Positioning, Navig DARPA Advances Alternative Navigation Technologies for GPS-Denied Environments T By John Haystead The Journal of Electronic Defense | February 2016 22 The Global Positioning System (GPS) has provided a tremendous leap forward in navigation technology - rapidly asserting itself as an essential, and often taken-for-granted, element in any number of applications, both civilian and military. Today, constant GPS contact is critically important in the battlespace. According to DARPA analysis, "Within 30 seconds of a GPS shut-down, a GPS receiver would only be able to specify that it was somewhere within an area the size of Washington, DC. An hour of GPS shutdown would expand the area of uncertainty to more than the size of Montana. As such, the longer that earthor aircraft-based clocks can maintain extreme accuracy will be a critical factor in the absence of GPS." However, the truth is that GPS was never intended to be a fail-safe resource, or to operate in all environments. As with most technologies, in designing the system, engineers had to make tradeoffs in order to make it practical and affordable. One of these tradeoffs was to accept that the system would provide relatively weak signals in lieu of launching extremely powerful transmitters into space. The downside to this, of course, is that these weak signals are easy to deny, degrade and spoof, posing a major problem for military users who need to operate in areas where adversaries will most certainly attempt to do just that. To overcome the limitations of GPS, DARPA is working on new, alternative Position Navigation Timing (PNT) technologies that explore new physics, utilize new devices, and incorporate new algorithms. The agency has actually been involved in PNT technology development for some time with a number of programs already officially winding down, but continuing to pursue work in some particularly promising areas. Many significant technological accomplishments are also being incorporated into next-phase programs, as well as spawning a number of all-new PNT research and development programs. Two principal program offices are involved in DARPA's PNT technology research - The Strategic Technology Office (STO) and Microsystem Technology Office (MTO). STO focuses on sys- tem-level technology, whereas MTO concentrates on component level development together with new fabrication processes and materials development. ANS Among the programs at STO, the Adaptable Navigation Systems (ANS) program was tasked to examine new technologies and techniques for advanced Inertial Navigation Systems (INS) that could provide extremely accurate inertial measurement of time and position without requiring external data sources. Focused on exploring new algorithms and architectures for rapid plugand-play integration of PNT sensors across multiple platforms, ANS is actually a portfolio of component programs with a common goal to reduce development costs and shorten the timeline to develop and field new PNT capabilities. Begun prior to 2010, and now nearing its conclusion, two remaining components of the program remain active. The Precision Inertial Navigation Systems (PINS) effort is developing an Inertial Measurement Unit (IMU) that uses cold atom interferometry technology for high-precision navigation without dependence on external fixes for long periods of time. Atom interferometry involves measuring the relative acceler-

Table of Contents for the Digital Edition of JED - February 2016

The View From Here
Conferences Calendar
Courses Calendar
From the President
The Monitor
World Report
Alternatives to Positioning, Navigation and Timing
Future Operating Environment 2035
Technology Survey: FPGA Boards
The Heat is On
EW 101
AOC News
Index of Advertisers
JED Quick Look

JED - February 2016