On Location at Stanford University by Per Enge (with the help of - - PowerPoint PPT Presentation

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On Location at Stanford University by Per Enge (with the help of - - PowerPoint PPT Presentation

Jan 16, 2024 209 likes •516 views

Thank you for inviting me to Calgary On Location at Stanford University by Per Enge (with the help of many) May 29, 2009 With Gratitude to the Federal Aviation Administration from Misra and Enge, 2006 2 GPS + Galileo + Compass + GLONASS 134

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On Location at Stanford University

by Per Enge (with the help of many) May 29, 2009 With Gratitude to the Federal Aviation Administration

Thank you for inviting me to Calgary

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from Misra and Enge, 2006

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GPS + Galileo + Compass + GLONASS 134 Navigation Satellites?

Frank van Diggelen’s new book from Artech

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Future GNSS Signals

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April 10, 2009 at 04:58 Pacific Time

from Table Mountain, Colorado

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Outline

  • Approach & Landing of Civil Aircraft
  • Gravimetry Using Cold Atoms
  • Geo-security
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Approach & Landing

Free of ionospheric influence. Robust against RFI (scheduled, accidental or malevolent). Worldwide approach capability with no airport equipment. Worldwide landing capability in all weather.

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Safety: Faults & “Rare Normal” Events

October 1993 modulation fault 40 notable iono events during the last solar peak RFI events:

  • San Diego
  • St Louis
  • Santa Cruz

Clock “runoffs” 7/28/01, 5/26/03 6/11/03 & more April 10, 2007 ephemeris fault & 24 smaller faults

  • ver the last 5 years
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LPV-200 Coverage on February 27, 2009 (from the FAATC live feed)

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Near Term GBAS Installations (from Carlos Rodriguez to RTCA)

  • ver 1000 aircraft orders include GBAS avionics
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Truncation of the Error Tail

5 10 15 20 25 30 35 40 45 0.02 0.04 0.06 0.08 0.1 0.12 0.14

User Vertical Position Error (meters) PDF

ground screening (Cat I) air & ground screening (Cat I/II/III) dual freq. GBAS (Cat I/II/III)

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PRN 1 Bias on L1

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Evolution of GNSS-Based Safety

L1 Only

  • RAIM
  • SBAS
  • GBAS

Dual freq. SBAS & GBAS

  • 24 SVs Minimum
  • 10-4 from GNSS

Dual freq. ARAIM

  • Open service
  • GPS: 30+ Slots
  • Multi-constellation
  • 10-4 from GNSS

2020 2030 2010 GNSS Integrity Within

  • GPS IIIC (1st 14) ++, or
  • GNSS Safety of Life
  • 24 SVs (GPS alone)
  • 10-7 from GNSS

Civil security (DoS & spoofing)

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Dual Frequency WAAS Convert Orange to Green

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System Definition ARAIM for 2020

VPL

GPS Compass Galileo GLONASS

VPL VPL VPL

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Trade Between Constellation Strength & Multiplicity of Ground Monitors (from Juan Blanch)

ARAIM 99.5% coverage 24-1 24 27-1 27 30-1 30 No Real Time Monitoring 3.7% 27.5% 9.56% 87.9% 79.8% 99.6% 8 stations 50.8% 88.3% 71.5% 96.7% 98.7% 100% 38 stations 71.2% 98.9% 90.0% 100% 99.9% 100% Civil monitoring is a trade between:

  • Constellation size
  • Robustness to SV failures
  • Network size (URA bounding)
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Stanford Atom-based Inertial Sensors 5 m/hour Versus 500 m/hour (from Stanford’s Mark Kasevich) Cesium atoms are proof masses. Pulses of laser light measure relative motion between atoms and case.

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Mobile Gravity Gradient Survey (from Mark Kasevich)

RTK from Trimble

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Gravity Gradient Survey of End Station III (from Mark Kasevich & Jeff Fixler)

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Gravity Meter (from Helicon Publishing)

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Airborne Gravimetry (from M. Dransfield, FUGRO)

Ore deposits

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Airborne Gravimetry

  • Atom gravimeter to measure gravity field at 10-6 level
  • High performance GPS or laser to decouple platform motion
  • Overfly region of interest
  • Water table monitoring
  • Homeland security
  • Resource discovery & management (oil/mineral)
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Reference System Requirements

  • Blimp dynamics

– equivalence principal – remove blimp acceleration from gravity measurements – mm accuracy for 100 second

  • Terrain to estimate nominal gravity

– accuracy to fraction of feature size – sub meter position

  • X band
  • Visual
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Geo-encryption (from Stanford’s Di Qiu)

Calibration Stage

Database Receiver

Verification Stage

Match? Feature Extraction Geotag Generation Receiver Feature Extraction Geotag Generation Grant or Deny Receiver

Attacker

Match? Feature Extraction Geotag Generation Low Temporal Decorrelation High Spatial Decorrelation

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Tamper-proof Hardware & Self-Authenticating Signal

Calibration

Database Receiver

Verification

Match? Feature Extraction Geotag Generation Receiver Feature Extraction Geotag Generation Grant Deny Loran with TESLA Receiver

Attacker

Match? Feature Extraction Geotag Generation Tamper-proof attack not possible

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Parking Lot Attack

Verification

Match? Loran with TESLA Receiver Feature Extraction Geotag Generation

Attacker

  • nearby
  • hopes that his received data falls within geo-fence
  • efficacy improves with proximity
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Smart Parking Lot Attack

Verification

Match? Loran with TESLA Receiver Feature Extraction Geotag Generation

delay delay delay delay

+

Attacker

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Smart Parking Lot Attack

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Multiplicity of Signal Characteristics

Verification

Match? Loran with TESLA Receiver Feature Extraction Geotag Generation

Attacking Node #1 Attacking Node #2

delay delay delay delay

+ WiFi Link Level Security? Any Other Good Candidates (UWB, TV, etc.)

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Conclusions

  • Potential utility provided by new PNT

technology is stunning.

  • International cooperation is needed to fully

realize these benefits.