adding resilience and trust to gps
TRANSCRIPT
Adding Resilience & Trust to GPS
STL
Copyright Orolia January 2017
• New signal available today• Broadcast on the Iridium sats
• >30 dB stronger than GPS• Higher jamming and
interference resistance• Operates indoors
• Encrypted signal• Inherently anti-spoof• Subscription based service• Available for civilian use
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STL – Satellite Time & Location Signal
from
The Ideal method for augmenting GPS to combat jamming and spoofing
Iridium STL
66 Iridium SatellitesGlobal coverage500 mile altitude1000x stronger
than GPS
24 GPS SatellitesGlobal coverage12,500 mile altitude25x further away
GPS
from
Copyright Orolia January 2017
Signal Comparison to GPSGPS SPS L1 STL
Timing accuracy to UTC ~20 ns ~200 ns
Positioning accuracy ~3 meters 30-50 meters
Time To First Fix -- Timing ~100 seconds ~few seconds
Time To First Fix -- Positioning ~100 seconds ~10 minutes
Anti-spoofing No, only for military use Yes, encrypted signal
Coverage Global Global
Availability Outdoors With view of horizon to getaccurate position with low DOP
Limited view of sky lengthensconvergence time
Availability Indoors No Yes: 30 – 40 dB stronger
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Copyright Orolia January 2017
• Re-purposed paging channels• 1620 MHz band, 25 KHz
channel, QPSK• Spread Spectrum coded
signal, 90 msec frame, ~1.4 sec burst on average
• UTC synchronized timing• +/- 500 nsec spec• 100-200 nsec typical
• Timing updates to a precision local oscillator for continuous time and frequency sourcing
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Timing signal - How it works
Copyright Orolia January 2017
Sub-microsecond Timing Worldwide
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1 microsecond
STL Standard Deviation: STL Max Excursion:
0.057 microseconds0.332 microseconds
Copyright Orolia January 2017
• Iridium: ~100 minute orbit• GPS: 12 hour orbit• Encrypted signal with
subscriber keys• Positioning determination
• Spot beam location (gross)• Range and Doppler updates• Convergence over minutes
• Geo-location security
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Low Earth Orbit (LEO) => Strong Signal with Spot Beams
Copyright Orolia January 20177
Global STL Coverage
Copyright Orolia January 2017
• Time Sync• Augment GPS with an independent
stronger signal• Anti spoof with subscriber
authenticationof encrypted signal
• Deep Indoor Penetration• No outdoor installation or cabling
required• 1000x stronger than GPS
• Trusted Location• Security based on geo-location
Benefits
Copyright Orolia January 2017
Indoor Timing Solutions
• Network time synchronization currently requires GPS• Data Centers• Payment Card Compliance• Secure Facilities
• GPS roof antennas are a “nightmare”• Landlord permission / roof rights• Zoning restrictions in major cities• Building hazards (e.g. asbestos)• Outdoor equipment maintenance• Typical installation $10k + $1k/month
• Same needs apply to data centers
Building image from Greg Jacobs, Bicsi
GPS
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STL
Copyright Orolia January 2017
STL – adding Resilience & Trust to GPS
GPSSTL
Atomic Holdover
Clock
A new service available from Spectracom