Boeing Timing & Location

Transcription

1 Boeing Defense, Space & Security PhantomWorks Boeing Timing & Location An Indoor Capable Time Transfer and Geolocation System Presentation Stanford PNT Symposium David Whelan Gregory Gutt Per Enge November 2011 BOEING is a trademark of Boeing Management Company. Copyright 2011 Boeing. All rights reserved. 1

2 Boeing Timing & Location (BTL) Ubiquitous coverage Improves yield for all E911 calls Consistent performance in rural Areas with no additional infrastructure Minimizes county exclusions due to rough terrain or low tower density High power and rapid motion Improved penetration In challenging environments New femtocell / cellular handset and retrofit SIM card implementations To speed capability and time to compliance A new capability that can improve E911 location performance and public safety in the near term 2 Copyright 2011 Boeing. All rights reserved. 2

3 Boeing s BTL Enhancement of Iridium: A Robust, GPS Independent Navigation System BDS PhantomWorks Physical Attributes of the BT&L Signal Frequency: MHz 20.32mSec QPSK bursts aligned on 90mSec Frames xgps burst received by user ~1/sec Signals received within 45dB of attenuation 15dB processing gain, 30dB link margin Buildings, cargo containers etc Well demonstrated HW and SW for 100m geolocation Iridium Background Primary Purpose: Global, Micro-Aperture Communication User Base: Military, Civil, and Commercial Over 300,000 subscribers as of 2008 Constellation Size: 66 Satellites Altitude: Low Earth Orbit (LEO) Boeing is Engineering and Operations Subcontractor to Iridium Iridium NEXT repopulation contracting underway Boeing Iridium Enhancements Time Xfer FDOA TDOA Creating the First Global Integrated Nav-Com System & Business 3 Copyright 2011 Boeing. All rights reserved. 3 3 Copyright 2011 Boeing. All rights reserved. 3

4 BTL Geo-location Builds on Transit Heritage Moore s Law Enables Performance Unachievable in the 1960s U.S. Transit Navigation Satellites provided 500 m Navigation Error Performance limited in part by onboard clock error Iridium + Ground Reference Network creates Effectively-Perfect Clock 2011: BTL SV Footprint LEO Orbit Plane Trace 1962: Transit Contours of Constant Range Rate LEO Position after ~100 sec Initial User Clock Frequency Error User Position Error Upon LEO Acquisition (bracketed by Doppler uncertainty at two separate epochs) Initial LEO Position BTL leverages both Transit and GPS Heritage: Low Earth Orbit Provides Rapid Angle Motion and Spatial Diversity for a Geometry Rich Solution Copyright 2011 Boeing. All rights reserved. 4 Copyright 2011 Boeing. All rights reserved. 4 4

5 BTL Geo-Location Provides Key Technical Advantages Boeing Secret Sauce 2 Parts (GPS-based Systems Can Not Do This) 1) Iridium Signal Power (BTL) >> GPS Penetrates Buildings Better 2) Spot Beams Form Unique Local Contours Extremely Difficult to Spoof Beams can readily segregate regions Spoofer (red) can t receive signals intended for legitimate user (yellow) Copyright 2011 Boeing. All rights reserved. 5

6 BDS PhantomWorks Iridium Footprint, Spot Beams & Command and Control Copyright 2011 Boeing. All rights reserved. Iridium footprint for each SV ~ CONUS 48 spot beams ~ typical US state SVs fully networked Control center in Leesburg VA Existing infrastructure manages broadcasts Broadcasts controlled at the beam level 6

7 Measured Signal-to-Noise Ratio for Iridium Signals at an Open Site and Inside a Metal Storage Container blue points: Iridium in container red line: GPS outdoors green points: Iridium outdoors Copyright 2011 Boeing. All rights reserved. 7

8 Line of Sight Vectors for GPS and Iridium for 200 Seconds The GPS vectors are shown in red; the Iridium vectors are shown in blue; and the buildings are on Stanford campus. Copyright 2011 Boeing. All rights reserved. 8

9 Boeing Timing & Location Modes Precise time and frequency aiding for increased GNSS signal sensitivity and quicker time to first fix Hybrid Iridium/GNSS satellite ranging Augment with Iridium SVs when insufficient GNSS SVs in view Iridium-Aiding GNSS Capabilities Transit like deep indoor positioning Boeing s Iridium-Only Ranging (IOR) Capability Copyright 2011 Boeing. All rights reserved. 9

10 Boeing Timing & Location Positioning Under Occlusion Operational Architecture GPS SV Positioning signal Iridium SV Loud Clock in Space Precision time signal coded on Iridium SV Data is Integrated at the Operations Server and included in the broadcast to unconnected users. Ops Server Iridium control center Provides: Iridium orbit data and clock biases for each SV. Attenuation Data is Integrated at the Operations Server and distributed via the cell network to connected users for faster time to first fix. Handset receives precise clock signal and uses it to aid GNSS acquisition and perform geo-location using Iridium alone if GNSS signal not available Copyright 2011 Boeing. All rights reserved. 10

11 Boeing Timing & Location Provides Superior Dual Mode Positioning (Aid GPS or Stand-Alone) Geo-Location Signal from Iridium Only GPS Attenuation Level Boeing/ Iridium-Only Range GPS Aided by BTL Broadcast message Acquisition Threshold Advertised Aided Commercial C(A) Acquisition Threshold (A-GPS Cell phones) db db 25 db db Iridium Only Geo-Location Value Region Iridium Data Aiding Value Region Boeing/ Iridium-Aiding GPS Range Advertised Un- Aided Commercial C(A) Acquisition Threshold (unconnected PND s) Wooden Building Brick-faced Masonry 2 Level Parking Structure Small Commercial Building Typical North American Residence Indoor Arena/Mall Dense Urban Environment Boeing's Location Technology Aiding Enhances Positioning in Typical GPS Operating Environments and Adds Robust Iridium-Only Geo- Location in Dense Urban Environments Copyright 2011 Boeing. All rights reserved. 11

12 Iridium LEO Orbits Effect in Urban Canyons Iridium Occlusion Iridium SVs have rapid geometry change The Iridium Orbit Period is 100 min GPS Orbit Period is 12 hours If GPS conditions are not favorable (< 4 sats), at least one Iridium BTL signal is likely to be in view to provide the additional signal(s) required to obtain a position fix BTL signals continuously available GPS 4 GPS SVs in View Conditions for Successful Position Fix 3 GPS SVs in view 1 BTL Iridium SV in view Plot shows visibility change of an Iridium SV over about 10 minutes vs. several 40 minute GPS tracks At least one Iridium SV always in view 2 GPS SVs in view 1 BTL Iridium SV in view 1 GPS SVs in view 1 BTL Iridium SV in view 1 BTL Iridium SV in view BTL Rapid Motion Helps Ensure Visibility of Iridium SVs in Urban Canyons Copyright 2011 Boeing. All rights reserved. 12

13 Indoor BTL Geolocation Tested in: Malls, Offices and Cargo Containers File#, Lat, Long, Description , Bottom parking struct , nd story , Then rov N/S on 2nd story , st Story , st Story , Then rov N on 1st Story , rd Story , Bottom parking struct Copyright 2011 Boeing. All rights reserved. 13

14 BDS PhantomWorks Boeing Bldg 17 Test locations ( ) Test points #9 2nd floor office w/ Window #10 2nd floor open cubicle (no window) Copyright 2011 Boeing. All rights reserved. 14

15 BDS PhantomWorks Low Cost User Equipment Development 30m/100m Ref Circles From Truth < 30m Geolocation Indoor Accuracy Leveraging Differential BTL System Copyright 2011 Boeing. All rights reserved. USB Stick Prototype Receiver Enabled By $2 Rx Chip Total BOM < $20 Plugs into a PC Board about the size of business card 15

16 BTL R&D Team Acknowledgements ikare Corporation Gregory Gutt BTL Chief Scientist Michael Eglington Geolocation Kalman Filter David Lawrence dbtl / BTL Signal Processing Stewart Cobb Small Scale Receiver Design Michael O Connor BTL Network Applications Stanford Per Enge Advisor / BTL Applications Boeing Jim Lassa Signal in Space / Lead Engineer Heiko Jones Signal Processing / USRP Receiver Design Cliff Kelley Signal Processing / USRP Receiver Design Chris Martens Geolocation Kalman Filter Copyright 2011 Boeing. All rights reserved.