I Hear, Therefore I know where I am: Exploiting Signals of Opportunity for Robust and Accurate Navigation in GPS-Denied Environments
Abstract
This project will develop a coherent analytical foundation, a suite of algorithms and tools, and software and hardware prototypes for an innovative framework to enable robust and accurate positioning, navigation, and timing (PNT) in environments where Global Positioning System (GPS) signals are challenged or denied. Our transformative framework assumes minimal a priori knowledgeabout the environment, performing on-the-fly multi-radio simultaneous localization, timing extraction, and signal landscape mapping. In this framework, a radio eavesdrops on unknown ambient radio frequency (RF) signals of opportunity (SOPs), such as cellular, television, and satellite communications, extracting opportunistically relevant positioning and timing information. The extracted information is synergistically fused to (1) build a spatiotemporal signal landscape map of the RF environment within which the radios simultaneously localize themselves in space and time and (2) aid the inertial navigation system (INS) in a tightly-coupled fashion. The extracted information is also shared among multiple radios over communication networks when available. Theproposed research will make PNT systems of future manned and unmanned Naval air, surface, and ground platforms and forces more resilient and accurate whenever GPS signals get compromised.The current PNT paradigm will not meet the demands of future manned and unmanned intelligence, surveillance, and reconnaissance and weapon systems to operate in highly-contested electromagnetic environments. The current PNT paradigm is non-networked, signal-similar, inflexible, and is ultimately traced to weak GPS signals from a single satellite constellation. GPS has become a single point of failure in the current PNT paradigm. We propose a shift from thisparadigm to a modernized system architecture that mitigates the shortcomings of the current PNT paradigm, one that is networked, collaborative, adaptable, and signal-diverse. SOPs are promising reliable and accurate PNT sources since they enjoy several advantages over GPS: they are (1) ubiquitous, (2) received at a significantly higher power, (3) diverse in frequency and direction, and (4) free to use, since they are already being transmitted for other purposes.Our proposed research considers the following motivating scenario. An unmanned aerial vehicle (UAV) enters an area of operation with clear access to GPS signals. Hostile ground forces initiate a jamming attack that effectively denies GPS signals. The UAV eavesdrops on ambient terrestrial and space-based SOPs, building a signal landscape map of the RF environment, aidingits INS, and continuing its mission with little degradation in PNT accuracy. A second UAV arrives. The two share PNT data, and they continuously refine the global signal landscape. The ground forces initiate a spoofing attack on other Global Navigation Satellite System (GNSS) signals. The diverse portfolio comprising the signal landscape map enables the UAVs to quickly detect thatthese GNSS signals are untrustworthy, and they subsequently stop using them.Our research addresses the Navy~s high-priority objective of accurate, reliable, maintainable, and affordable PNT in GPS-denied environments. Specifically, our project aims to (1) establish foundational theory for optimal exploitation of terrestrial and space-based SOPs for PNT, (2) characterize error sources and error budgets associated with exploiting SOPs for PNT, (3) developstrategies for mitigating on-the-fly SOPs~ intermittency, degradation, and errors, (4) synthesize collaborative navigation frameworks with performance guarantees, (5) characterize tradeoffs between collaboration cost and PNT performance improvements, and (6) develop a testbed of UAVs and ground vehicles equipped with cognitive software-defined radios for experimental verification.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 30, 2019
- Source ID
- N000141912511
Entities
People
- Zaher M. Kassas
Organizations
- Naval Information Warfare Center Pacific
- Office of Naval Research
- United States Navy