Cognitive Opportunistic Navigation with Unknown LEO and MEO Satellite Signals
Abstract
This project plans to develop a transformative framework to enable resilient and accurate positioning, navigation, and timing (PNT),in GPS-denied and GPS-degraded environments by exploiting low and medium Earth orbit (LEO and MEO) satellite signals. We propose to,develop a coherent analytical foundation, a suite of algorithms and tools, and software and hardware prototypes for an innovative PN,T system that we call: cognitive opportunistic navigation (CON). Our revolutionary framework assumes minimal a priori knowledge abou,t the radio frequency (RF) environment and learns unknown LEO and MEO signals in a cognitive fashion, turning these signals into our, own dedicated PNT sources.In this framework, software-defined radios (SDRs) (e.g., mounted on a Navy carrier or a high flying aeria,l vehicle) eavesdrop on unknown ambient RF signals of opportunity (SOPs) from LEO and MEO satellites, which are not intended for PNT, (e.g., Starlink LEO, OneWeb LEO, Kuiper LEO, and O3b MEO). The SDRs sense the spectrum in a cognitive fashion to (i) detect unknown, beacons of transmitting LEO and MEO SOPs, (ii) identify the number of transmitting LEO and MEO sources and associate them with each, transmitting beacon, (iii) decipher relevant PNT information from each LEO and MEO SOP, and (iv) track the SOP to produce navigatio,n observables (pseudorange, Doppler, and carrier phase). Subsequently, the SDR builds a spatiotemporal signal landscape map of the R,F environment, which is shared with other radios (e.g., mounted on aerial vehicles, Naval vessels, dismounted Marines, etc.) to ena,ble them to navigate exclusively with LEO and MEO SOPs, without relying on GPS signals. Specifically, our project aims to pursue the, following tasks: (1) Signal acquisition: (i) signal activity detection and spectrum sensing, (ii) estimation of the number of sourc,es in the unknown RF environment, (iii) beacon length estimation, and (iv) deciphering the beacon samples, (2) Simultaneous signal t,racking and beacon estimation, (3) Data association.The proposed project considers the following scenario. A Navy carrier enters an,area of operation with clear access to GPS and other GNSS signals. Alerted to the carriers presence, hostile ground forces initiate,a multi-kW jamming attack that effectively denies signals at all GPS frequencies. The carrier loiters gathering signal intelligence,(SIGINT) surveillance data, employing the proposed CON framework to eavesdrop on unknown ambient RF SOPs from LEO and MEO satellites,, which are not intended for PNT. The carrier-mounted SDRs sense the spectrum in a cognitive fashion to (i) detect unknown beacons o,f transmitting LEO and MEO SOPs, (ii) identify the number of transmitting LEO and MEO sources and associate them with each transmitt,ing beacon, (iii) decipher relevant PNT information from each LEO and MEO SOP, and (iv) track the SOPs to produce navigation observa,bles (pseudorange, Doppler, and carrier phase). Subsequently, the SDR builds a spatiotemporal signal landscape map of the RF environ,ment, which is shared with other radios (e.g., mounted on aerial vehicles, Naval vessels, dismounted Marines, etc.) to enable them t,o execute their mission in a safe and effective fashion, while navigating exclusively with LEO and MEO SOPs, without relying on GPS,signals.The proposed research will make PNT systems of future manned and unmanned Naval air, surface, and ground platforms and force,s more resilient and accurate whenever GPS signals get compromised.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 05, 2022
- Source ID
- N000142212242
Entities
People
- Zaher M. Kassas
Organizations
- Office of Naval Research
- Ohio State University
- United States Navy