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 Navigation Satellites? Frank van Diggelen s new book from Artech 3
Future GNSS Signals 4
April 10, 2009 at 04:58 Pacific Time from Table Mountain, Colorado 5
Outline Approach & Landing of Civil Aircraft Gravimetry Using Cold Atoms Geo-security 6
Approach & Landing Worldwide approach capability with no airport equipment. Worldwide landing capability in all weather. Free of ionospheric influence. Robust against RFI (scheduled, accidental or malevolent). 7
Safety: Faults & Rare Normal Events October 1993 modulation fault Clock runoffs 7/28/01, 5/26/03 6/11/03 & more 40 notable iono events during the last solar peak RFI events: San Diego St Louis Santa Cruz April 10, 2007 ephemeris fault & 24 smaller faults over the last 5 years 8
LPV-200 Coverage on February 27, 2009 (from the FAATC live feed) 9
Near Term GBAS Installations (from Carlos Rodriguez to RTCA) over 1000 aircraft orders include GBAS avionics 10
Truncation of the Error Tail dual freq. GBAS (Cat I/II/III) 0.14 0.12 0.1 air & ground screening (Cat I/II/III) ground screening (Cat I) 0.08 PDF 0.06 0.04 0.02 0 0 5 10 15 20 25 30 35 40 45 User Vertical Position Error (meters) 11
PRN 1 Bias on L1 12
2010 Evolution of GNSS-Based Safety 2020 2030 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 Civil security (DoS & spoofing) GNSS Integrity Within GPS IIIC (1 st 14) ++, or GNSS Safety of Life 24 SVs (GPS alone) 10-7 from GNSS 13
Dual Frequency WAAS Convert Orange to Green 14
System Definition ARAIM for 2020 GPS VPL VPL VPL VPL Compass Galileo GLONASS 15
Trade Between Constellation Strength & Multiplicity of Ground Monitors (from Juan Blanch) Civil monitoring is a trade between: Constellation size Robustness to SV failures Network size (URA bounding) ARAIM 99.5% coverage No Real Time Monitoring 24-1 24 27-1 27 30-1 30 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% 16
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. 17
Mobile Gravity Gradient Survey (from Mark Kasevich) RTK from Trimble 18
Gravity Gradient Survey of End Station III (from Mark Kasevich & Jeff Fixler) 19
Gravity Meter (from Helicon Publishing) 20
Airborne Gravimetry (from M. Dransfield, FUGRO) Ore deposits 21
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) 22
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 23
Geo-encryption (from Stanford s Di Qiu) Receiver Feature Extraction Geotag Generation Database Low Temporal Decorrelation Calibration Stage Match? Grant or Deny High Spatial Decorrelation Receiver Feature Extraction Verification Stage Geotag Generation Match? Receiver Feature Extraction Geotag Generation Attacker 24
Tamper-proof Hardware & Self-Authenticating Signal Loran with TESLA Receiver Calibration Feature Extraction Geotag Generation Database Match? Grant Deny Receiver Feature Extraction Geotag Generation Verification attack not possible Tamper-proof Match? Receiver Feature Extraction Geotag Generation Attacker 25
Parking Lot Attack Loran with TESLA Verification Match? Receiver Feature Extraction Geotag Generation Attacker nearby hopes that his received data falls within geo-fence efficacy improves with proximity 26
Smart Parking Lot Attack Loran with TESLA Verification Match? delay Receiver Feature Extraction Geotag Generation delay delay + Attacker delay 27
Smart Parking Lot Attack 28 28
Multiplicity of Signal Characteristics Loran with TESLA Attacking Node #1 WiFi Link Level Security? Verification Attacking Node #2 Match? Any Other Good Candidates (UWB, TV, etc.) delay delay + Receiver Feature Extraction Geotag Generation delay delay 29
Conclusions Potential utility provided by new PNT technology is stunning. International cooperation is needed to fully realize these benefits. 30