GNSS Interference: Situational Awareness and LEO Backup

Global Navigation Satellite System (GNSS) receivers in Low Earth Orbit (LEO) are a proven asset for detecting, classifying, and geolocating terrestrial GNSS interference that can be a danger to civil aviation, maritime, or ground vehicle traffic. Emitter geolocation from LEO offers worldwide coverage with a frequent refresh rate, making it possible to maintain a common operating picture of terrestrial sources of interference. The research team proposes to further develop and demonstrate techniques whereby GNSS interference signals captured by a single satellite or by multiple satellites can be used to characterize and geolocate the signals’ source. In particular, the team will pursue so-called direct techniques that yield geolocation solutions even in cluttered (many interference sources) environments. A particular challenge the team seek to overcome is making direct techniques more efficient to enable “quick scan” geolocation. A secondary thrust of this project will be to further study the possibility of using signals from mega-constellations of LEO satellites designed for broadband communications as a backup to GNSS for PNT. The team has already identified structures in Starlink signals that will be useful for measuring the time of arrival (TOA) of Starlink frames. But whether the team can form pseudo range measurements that are useful for PNT remains an open question whose answer depends on the timing properties of the Starlink signals. The team will seek to elucidate these timing properties. Moreover, the team will seek to answer the following questions: (1) From how many unique SVs, on average, can a user receive assigned or side beams strong enough for accurate TOA measurements? (2) Is there a simple pattern that can be used to predict channel-beam-SV assignments? (3) What is the range of absolute received power into a hemispherical antenna for an assigned or side beam?


  • English


  • Status: Active
  • Funding: $285000
  • Contract Numbers:


  • Sponsor Organizations:

    Office of the Assistant Secretary for Research and Technology

    University Transportation Centers Program
    Department of Transportation
    Washington, DC  United States  20590
  • Managing Organizations:

    Center for Automated Vehicle Research with Multimodal Assured Navigation

    Ohio State University
    Columbus, OH  United States  43210
  • Project Managers:

    Kline, Robin

  • Performing Organizations:

    University of Texas at Austin

    Austin, TX  United States  78712
  • Principal Investigators:

    Humphreys, Todd

  • Start Date: 20231030
  • Expected Completion Date: 20240830
  • Actual Completion Date: 0
  • USDOT Program: University Transportation Centers Program

Subject/Index Terms

Filing Info

  • Accession Number: 01901379
  • Record Type: Research project
  • Source Agency: Center for Automated Vehicle Research with Multimodal Assured Navigation
  • Contract Numbers: 69A3552348327
  • Files: UTC, RIP
  • Created Date: Dec 4 2023 5:27PM