Category:GNSS-Denied Navigation

GNSS (Navstar GPS (USA), GLONASS (RU), Beidou (CN), Galileo (EU)) might encounter jamming or spoofing. See https://gpsjam.org/ for daily maps of interference.
Note: Galileo is now hardened by authentication (OSNMA) https://insidegnss.com/osnma-necessary-but-not-sufficient-for-gnss-security/
This page lists some alternative (marine) navigation strategies:

cross bearings

• https://de.wikipedia.org/wiki/Kreuzpeilung

tools

• bearing compass https://en.wikipedia.org/wiki/Bearing_compass
• OpenCPN:
  • https://opencpn.org/OpenCPN/plugins/draw.html

dead reckoning

• https://en.wikipedia.org/wiki/Dead_reckoning

tools

• compass
• log https://en.wikipedia.org/wiki/Chip_log#More_modern_logs_and_replacements
• OpenCPN:
  • https://opencpn.org/OpenCPN/plugins/dreckoning.html
  • https://opencpn.org/OpenCPN/plugins/draw.html

celestial navigation

• https://en.wikipedia.org/wiki/Celestial_navigation

tools

• sextant https://en.wikipedia.org/wiki/Sextant
• OpenCPN:
  • https://opencpn.org/OpenCPN/plugins/celestialnav.html

inertial navigation

• https://en.wikipedia.org/wiki/Inertial_navigation_system

equipment

• gyroscope
  • https://www.anellophotonics.com/blog/reinventing-the-optical-gyroscope-with-silicon-photonics
• accelerometer

radio direction finding

Measuring incoming signals’ AoA (Angle of Arrival) relative to the vehicle (bearing).

• https://en.wikipedia.org/wiki/Direction_finding
• GNSS-Denied Navigation using Direction of Arrival from Low-Cost Software Defined Radios and Signals of Opportunity

equipment

• https://www.qsl.net/df9ie/kraken--kerberos-sdr.html
  • KerberosSDR
  • KrakenSDR

R(anging)-Mode

R-Mode is intended to become a ground based GNSS backup.

• https://www.navigation-mac.fr/r-mode-futur-systeme-de-positionnement-alternatif/?lang=en
• https://en.wikipedia.org/wiki/Trilateration

MF (medium frequency)

• Testbed at baltic sea made use of 7 DGPS-stations:
  • https://www.r-mode-baltic.eu/
    • https://www.r-mode-baltic.eu/wp-content/uploads/2022/11/Final_report_R-Mode_Baltic2_v1.0.pdf
• standardization:
  • https://interreg-baltic.eu/project-posts/ormobass/important-step-towards-r-mode-standardization/
    • https://www.iala.int/product/g1187-medium-frequency-r-mode-signal-structure-and-navigation-message/
• DGPS-stations:
  • https://www.iala.int/technical/positioning-navigation-and-timing/world-dgnss-stations-list/
  • https://overpass-turbo.eu/s/2axW

equipment

• RTL-SDR
  • R-Mode: An Alternative to Global Navigation Satellite Systems for Terrestrial Navigation at Medium Frequencies

VHF (very high frequency)

Testbed at baltic sea made use of 4 AIS base-stations.

• https://www.r-mode-baltic.eu/
• AIS R-Mode Trilateration for GPS Positioning and Timing Insurance
• ...

radar

Accurate vessel positioning with radar and digital elevation models.

• https://library.e.abb.com/public/7e2b429f4b684e1ca576a57697ed9b68/GNSS-free%20navigation.pdf

equipment

• ...