Presentation on theme: "Durk van Willigen 1 reelektronika The Challenge of Finding Your Position in a World Hostile to Radio Navigation Prof.dr. Durk van Willigen Reelektronika,"— Presentation transcript:
Durk van Willigen 1 reelektronika 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
Durk van Willigen 2 reelektronika 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
Durk van Willigen 3 reelektronika 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
Durk van Willigen 4 reelektronika 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 !!
Durk van Willigen 5 reelektronika 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
Durk van Willigen 6 reelektronika 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
Durk van Willigen 7 reelektronika 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?
Durk van Willigen 9 reelektronika 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
Durk van Willigen 10 reelektronika L1 spectrum (USA in action) Spot Beam Mode -138 dBW (+20 dB) 156515801575158515901570 15551595 1560 All non M-code signals on L1, L2, and L5 can be denied
Durk van Willigen 11 reelektronika 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?
Durk van Willigen 12 reelektronika 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
Durk van Willigen 13 reelektronika 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 !!
Durk van Willigen 14 reelektronika A Powerful Solution Avoid Single-Point-Failure Structure through integration of highly dissimilar sub-systems Which systems are dissimilar to GPS?
Durk van Willigen 15 reelektronika Integrated Navigation Concept
Durk van Willigen 16 reelektronika 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
Durk van Willigen 17 reelektronika Strengths/Weaknesses Navigation Galileo/GPS/GLONASSLoran-C/Chayka (Un-)intentional long-range interference robustness LowVery high Unintentional short-range interference robustness HighLow* AccuracyHigh / Very highMedium / High** Availability in urban areasMediumHigh ReliabilityHigh Initial provider costsHighMedium Recurring provider costsMediumLow * Interference from e.g. car generators, computer monitors, etc ** Medium accuracy with accurate ASF tables, high accuracy with DLoran-C or SLA technology
Durk van Willigen 19 reelektronika 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?
Durk van Willigen 20 reelektronika Frankfurt Down-Town Tall buildings and narrow streets in Financial Center of Europe GPS suffers from shadowing and multipath New Loran-C receiver not yet available at time of test
Durk van Willigen 21 reelektronika GPS only in Frankfurt 111 m/div 71 m/div
Durk van Willigen 22 reelektronika GPS-INS Integrated
Durk van Willigen 23 reelektronika Unaided Versus Aided GPS
Durk van Willigen 24 reelektronika TOA Tracking Accuracy @ Boston: 5m 95% Measurements in Boston harbor Integrate and dump every 5 seconds FAA LORAPP program (LORAPP = LORan Accuracy Performance Panel)
Durk van Willigen 25 reelektronika Local Interference Cancellation-1 Time Domain
Durk van Willigen 26 reelektronika Local Interference Cancellation-2 Frequency Domain
Durk van Willigen 27 reelektronika TOA Tracking Stability @ Boston Y-axis = 30 m/div Time jumps due to transmitter time control steps of 20 ns, equivalent to 6 m
Durk van Willigen 28 reelektronika Strengths/Weaknesses Augmentation WAAS/EGNOS/MSASEGNOS via Eurofix Long-range interference robustness High*Very low Short-range interference robustness LowMedium Availability in urban areasMediumHigh Availability in Polar RegionNoneHigh** ReliabilityHigh Initial provider costsHighVery low Recurring provider costsMediumVery low * 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
Durk van Willigen 29 reelektronika EGNOS/Eurofix Station at Sylt 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 Equipment Rack Antenna mounts Thales EGNOS GPS Antenna Eurofix Integrity Monitor GPS Antenna Eurofix Reference Station GPS Antenna Eurofix Datalink Monitor Loran-C Antenna
Durk van Willigen 31 reelektronika Integrated GPS/Loran/Eurofix Receiver Credit Card 85 x 54 mm Front End & ADC 77 x 47 mm Signal Processor 77 x 51 mm
Durk van Willigen 32 reelektronika H-Field Antenna Testing 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 Antenna under test H-field generating loop PC-controlled turn table
Durk van Willigen 33 reelektronika 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!!