Transcript Resilient Positioning, Navigation & Timing (PNT)

© David Last
Dover Strait – 28 days’ traffic records
Satellite and Control System Failures
Official announcement:
"A significant GPS anomaly occurred on 1 Jan 04, beginning at approximately
1833Z ... (which) … affected precise timing and navigation users over large
portions of Europe, Africa, Asia, Australia, and … North America … and resulted
in the transmission of Hazardously Misleading Information."
SVN23 clock failure
Sources: Vogel, Macabiau & Suard, ‘Effect of a GPS Anomaly on Different GNSS Receivers’, ION GNSS 2005, Long Beach, CA, Sep 13-16, 2005,
Hoppe & Walterfang, ‘Investigation of a GPS Satellite Problem with respect to DGPS and GPS users’, European Journal of Navigation, May 2004,
www.lr.tudelft.nl/live/pagina.jsp?id=400f4487-ed8c-4274-95cb-ebc2afa7385e&lang=en
© David Last
Solar flares
“The burst produced 20,000 times more radio emission
than the … rest of the sun … and swamped GPS
receivers over the entire sunlit side of the Earth.”
© David Last
Picture: www.flickr.com/photos/l23productions/1451697290/
© David Last
A small jammer on this cliff-top disrupted GPS on vessels
out to ranges as wide as the Dover Strait
Low-powered GPS jammer on ship
Jammer of less than 1 milliWatt:
• False positions, and velocities
• Autopilot may turn vessel
• But no alarms!
With a little more jammer power:
• Electronic Chart Displays
• Autopilot
• Automatic Identification System
• Differential GPS
• Satellite voice and data comms
• Maritime distress safety system
plus …
Ship’s Radar & Gyrocompass
© David Last
Jammers like this already on our streets can block all frequencies
of GPS and Galileo, Compass-Beidou & GLONASS, plus the
EGNOS, WAAS, QZSS & GAGAN augmentation systems.
xx
Pictures: www.jammer-store.com/gj5-gps-l1-l2-l5-jammer-blocker.html
© David Last
Pictures: wikipedia.org, dailymail.co.uk, insidegnss.com, youtube.com
eNa
eNavigation is coming!
Picture: General Lighthouse Authorities of the UK & Ireland
© David Last
Picture based on: http://www.amcsearch.com.au
Reduce impact of
GPS vulnerability
• Harden GPS systems
• Complementary navigation system
- independent of satellite navigation
- compatible with it
- meets modern standards
• Enhanced Loran (eLoran)
• GNSS + eLoran: So resilient you can reduce
lighthouses and buoys – and pay for eLoran
© David Last
The GLAs’ prototype eLoran system is on the air
Runs continuously; available since May 2010;
10-20m accuracy in ports with differential service (green area)
The GLAs’ prototype eLoran system is on the air
- serving the Port of Dover
and the UK section of the Dover Strait
First stage eLoran Initial Operational Capability (IOC)
- soon at 6 more busy ports
Pictures: www.poferries.com
On 28 February 2013, the Trinity House Vessel Galatea reverted
automatically to eLoran when GPS was jammed. Galatea
continued seamlessly on track, reporting eLoran positions to
nearby ships and the Vessel Traffic Service ashore.
Picture: General Lighthouse Authorities of the UK & Ireland
© David Last
Enhanced Loran
(eLoran)
• eLoran: Strong LF signals from earth
• GPS: Weak microwaves from space
• Both: timing, ranges, position, time
• No common mode of failure
• Plug-in replacement
Pictures: Mitchell Narins, Federal Aviation Administration; Reelektronika bv
© David Last
Differential eLoran for Port Approaches
with 10metre (95%) signal-in-space accuracy
• Map Additional Secondary Factors (ASFs) of signals
• Measure real-time signal variations at Reference Station
• Send corrections to receivers over eLoran data channel
Performance of the generations of Loran
eLoran has:
• Data channel: differential corrections and rapid failure warnings
• Advanced digital signal receivers tracking all stations in view
• High precision in ports
• Modern transmitting stations and procedures
Table: www.gla-rrnav.org/file.html?file=652be60e268e09c0d91c5b6a976fbc30
© David Last
The GLAs’ prototype eLoran system now provides
precise telecommunications timing
across the UK and Ireland
Picture: www.ursanav.com
The GLAs’ prototype eLoran system now provides
precise telecommunications timing
across the UK and Ireland
… plus secure data, with
road vehicle tracking planned.
Picture: www.ursanav.com
eLoran can also support Land Vehicle Telematics
Pictures: www.vehicletrackingltd.co.uk, www.olmc.eu,blogs.guardian.co.uk
© David Last
Timing & Data Transmissions from US Loran facilities
• Renaissance of US low frequency solutions
• US Coast Guard and UrsaNav co-operate
• ‘Skyfree’ timing from Loran facility
• Much faster Loran data channel
• Received indoors
Pictures: www.ursanav.com
© David Last
Far East Radio Navigation Service (FERNS)
Japan:
• No jamming has been observed
in Japan
• No plans for terrestrial systems
• All Loran-C stations removed
by 2015
South Korea:
• Plan to implement eLoran
• National coverage from 5 stations
North-West Europe
UK & Ireland:
• Developing eLoran
• Implementing Operational Capability
France:
• Transmitting Loran-C
• Has experimented with eLoran
Norway:
• Closing Loran-C transmissions
• Discussions with Russia re high north
Netherlands:
• Rotterdam pilots now using eLoran
The Route to eLoran
The Route to eLoran
Japan
Germany
USA?
Russia
ROK
UK
World-Wide Radionavigation Plan
Members of IALA with Loran facilities…
are encouraged to:
St Germain en
Laye, France
• Retain them in operation
• Make plans to upgrade to eLoran
• Support development of eLoran
Performance and technical standards are
under development by RTCM SC127.
• Upgrade old Loran-C to new eLoran
• Re-use Loran-C stations
• Serve shipping, telecoms, data, land
transport – critical infrastructure
• Maritime: positive payback, shared costs
• New markets for industry
• Maximise Loran-C payback