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The Challenge of Finding Your Position in a World Hostile to Radio Navigation

The Challenge of Finding Your Position in a World Hostile to Radio Navigation. Prof.dr. Durk van Willigen Reelektronika, Netherlands ILA 2003 Boulder, Colorado, USA, 3-7 November 2003. Overwhelming GPS Success. GPS revolutionised navigation GPS is embraced by its users GPS never fails 

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The Challenge of Finding Your Position in a World Hostile to Radio Navigation

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  1. The Challenge of Finding Your Position in a World Hostile to Radio Navigation Prof.dr. Durk van Willigen Reelektronika, Netherlands ILA 2003 Boulder, Colorado, USA, 3-7 November 2003

  2. Overwhelming GPS Success • GPS revolutionised navigation • GPS is embraced by its users • GPS never fails  • Emerging worries on GPS  • Concern  PCCIP  Volpe Report • US leads rethinking on vulnerability GPS • From sole-means dissimilar systems 

  3. Vulnerability a today’s Issue? • Yes, because society never relied so strongly on a single source of navigation and time before the GPS era • Yes, because never before the bad guys were able to disable our core navigation and time sources so easily and untraceably, and over such large areas • Yes, because many do not recognize this flaw and do not take timely precautions

  4. User’s Attitude • We have GPS, it performs excellent, it is extremely cost-effective, so why worry? • Question: Imagine living without fire fighters, vaccination, life-boats, police, dikes, … • We have them all, we generously pay for it, but we are convinced that we will never need them • Fortunately, we don’t need such precautions for GPS or GLONASS or Galileo because these systems are perfect !!

  5. Why Galileo next to GPS? • Because Europe is an industrial high-tech world player • Europe aims to be successful in GNSS technology just as it is with Airbus, ESA, Concorde, TGV, GSM, Bach, Rembrandt, …. • But like the US, Europe prefers to be auto-nomous in respect of navigation and timing • Europe is keen to make profit with its own Galileo business

  6. US-European Navigation Co-operation? • Users will like Galileo as it doubles the number of navigation satellites improving availability in city areas • Professional navigators think Galileo may reduce the single-point-failure effects in the technical and control segments • US military highly dislikes Galileo’s PRS as it makes GPS’ M-code less effective • PRS = Public Restricted Services

  7. PRS versus M-code • The US officially and repeatedly stated that it will deny all non-US satellite navigation services if US national security requires so • Europe would like to prevent that • Europe might also deny GPS to many other countries if needed • Question from a simple not involved observer: • Does the US rule GNSS like the UK ruled the waves? • Are the US and Europe each others hostages? • In all public statements these issues are not mentioned of course (ION-GPS 2003) • What is the discussion all about?

  8. GPS IIF Galileo 1560 1565 1570 1575 1580 1585 1590 1560 1565 1570 1575 1580 1585 1590 1555 1595 L1 spectrum (USA at ease) C/A / -157 dBW M-code / -158 dBW (Earth Coverage Mode) P(Y) / -160 dBW US-Europe Conflict OS / -152 dBW PRS / -152 dBW ? PRS / -152 dBW ?

  9. Denial Dilemma • Imagine that the US would ever like to deny GPS to non-US countries by jamming civil parts of GNSS bands • Then GPS CA and Galileo OS will stop  • OS = Open Service • So, the US continues with M-code and Europe with its PRS  • But if US would like to deny PRS also then it will harm its own M-code as well, or the other way around with identical effect 

  10. All non M-code signals on L1, L2, and L5 can be denied 1560 1565 1570 1575 1580 1585 1590 1555 1595 L1 spectrum (USA in action) Spot Beam Mode-138 dBW (+20 dB)

  11. Solution? • Increase GPS M-code signal power levels by e.g. 20 dB in selected areas so that jamming PRS will not kill M-code signals as a collateral damage  • But what will happen if Europe would take identical initiatives?  • Challenging issue for American and European politicians  • Or, is it a technical challenge only? 

  12. Who Might Endanger GNSS? • Hackers • Feels good to get large user groups on a string • Compare with virus creators • Road users • Attempt to cheat the system to get a free ride • Thieves • Disable car-theft protection systems • Disable GNSS-based tracking and tracing of valuable cargo • Terrorists • Use your own imagination and, please, don’t tell anybody the results

  13. Very Annoying L1 Dinky Toy • Low GNSS power levels makes jamming relatively easy • Just 100 Watts to illuminate 38% of earth’s surface • Much progress observed today in jamming rejection technology • Outside military world not yet available • Complex • Fail safe? • 1 mW L1 jammer • 100 meters range • 30 mm on a side • 4 hours on single battery • Not for sale !!

  14. A Powerful Solution • Avoid Single-Point-Failure Structure through integration of highly dissimilar sub-systems • Which systems are dissimilar to GPS?

  15. Integrated Navigation Concept

  16. Galileo backing up GPS? • Yes, because • Galileo has higher power level • Galileo uses some un-modulated carriers • More satellites yield better availability • If one control link fails the other one may survive • No, because • Low dissimilarity in frequency and power levels • Denial requirement of the other party • Conclusion: Other very dissimilar systems needed

  17. Strengths/Weaknesses Navigation * Interference from e.g. car generators, computer monitors, etc ** Medium accuracy with accurate ASF tables, high accuracy with DLoran-C or SLA technology

  18. GNSS versus Loran BSA = Beam Steering Antenna DSP = Digital Signal Processing

  19. Questions • If Loran is that good why are there no GPS-like receivers available? • Why are there no integrated GPS-Loran receivers? • How to integrate GPS and Loran-C? • Integrate or mutually calibrate? • What is the real error budget chain under adverse signal conditions? • Why are inertial sensors not integrated with Loran to increase dynamic response?

  20. Frankfurt Down-Town New Loran-C receiver not yet available at time of test Tall buildings and narrow streetsin Financial Center of Europe GPS suffers from shadowing and multipath

  21. GPS only in Frankfurt 111 m/div 71 m/div

  22. GPS-INS Integrated

  23. Unaided Versus Aided GPS

  24. TOA Tracking Accuracy @ Boston: 5m 95% Measurements in Boston harbor Integrate and dump every 5 seconds FAA LORAPP program (LORAPP =LORan Accuracy Performance Panel)

  25. Local Interference Cancellation-1 Time Domain

  26. Local Interference Cancellation-2 Frequency Domain

  27. TOA Tracking Stability @ Boston Y-axis = 30 m/div Time jumps due to transmitter time control steps of 20 ns, equivalent to 6 m

  28. Strengths/Weaknesses Augmentation *Not relevant as under jamming conditions GNSS will fail too ** To be confirmed by real-life tests in the Artic Region. Covering Polar Region requires US and Russian stations to broadcast DBAS data too

  29. EGNOS/Eurofix Station at Sylt Antenna mounts Equipment Rack EGNOS TRAN equipment ←Thales EGNOS Rx ← Modem & power supply ←EGNOS TRAN PC Existing Eurofix installation ←Eurofix Rx & power supply ←2x GPS Rx & Modem ←CPU switch ←Integrity Monitor PC ←Reference Station PC ←UPS Thales EGNOS GPS Antenna Eurofix Integrity Monitor GPS Antenna Eurofix Datalink Monitor Loran-C Antenna Eurofix Reference Station GPS Antenna

  30. 9990Y+7960Z 1,000 kW 7960M 560 kW 9990Y+7960Z 1,000 kW 5960X 1,200 kW 4970X+5960Y 250 kW 7001Y 250 kW 4970M+5960Z 1,200 kW 7270X+5930Z 800 kW 7001X+9007W 250 kW Polar Routes • Restricted Russian polar routes: Polar 1 to 4 • Preferred random routing in Canada • 2005: 9000+ commercial polar flights estimated • Savings: • Flying time: 2+ hrs • Costs: US$ 16 k/flight • Time slots Atlantic • ‘Polar Routes Feasibility Study’, Nav Canada and FAAR, October 2000

  31. Integrated GPS/Loran/Eurofix Receiver Credit Card 85 x 54 mm Front End & ADC77 x 47 mm Signal Processor77 x 51 mm

  32. Antenna testing requires many skills and lots of enthusiasm High performance Loran receivers need many aspects to be verified Most Loran-C challenges are known today, and are taken care of Loran development is a multi-disciplinary task Much progress observed in US, Asia and Europe H-Field Antenna Testing Antenna under test H-field generating loop PC-controlled turn table

  33. Conclusions • Loran-C/Chayka is the only wide area multi-modal navigation life boat if GNSS fails • Skywave and man-made interference largest challenge to Loran-C land applications • Loran-C receivers without GPS chip set may have a too low market appeal • With land applications low-cost rate gyros and odometers may be of good help to smooth tracking and to coast if both Loran and GPS fail • Large advances in Loran-C technology must now be marketed at high speed to create critical mass to keep Loran-C/Chayka alive!!

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