NovAtel Precise Thinking Makes it Possible

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1 NovAtel Precise Thinking Makes it Possible Advantages of Multi-Frequency Multi-Constellation GNSS Thomas Morley, Product Manager

2 Outline Who am I? What is GNSS? Where are we today with respect to GNSS? When will GNSS be a reality? Why is this important to you? How are GNSS manufacturers going to meet the challenges?

3 What - is GNSS? Global Navigation Satellite System Global Worldwide coverage not regional Navigation Provides position information Satellite Space-based System Space segment (satellites), ground segment (monitoring infrastructure), user segment (receivers), launch capability (rockets)

4 What GNSS are there? GPS (USA) GLONASS (Russia) Exist today Galileo (Europe) Formally announced and planned Compass (China) Announced, but future intentions?

5 What is not GNSS? Space-Based Augmentation Systems (SBAS) WAAS, EGNOS, MSAS, CDGPS Regional correction services Local Area Augmentation Systems (LAAS) Ground-based transmitters Commercial Correction Services OmniSTAR, StarFire, others Network RTK Others

6 Where - GNSS Today GPS The Global Positioning System (GPS) is the only fully operational GNSS in existence today Developed by the US Department of Defense Initial Operational Capability (December 8, 1993) Full Operational Capability (1995) 24 operational Block II/IIA satellites Currently 30 healthy satellites in orbit As of September 18, 2007

7 GNSS Today GPS Overview (as of September 18, 2007) 0 x Block-II October 1990 PRN 15 until March 14, x Block-IIA Design life: 7.3 years July 1991 November x Block-IIR July 1997 November x Block-IIR-M Design life: 7.8 years September 2005 November 2006 Next launch scheduled for October 17, 2007 One Block-IIR-M modified for an L5 payload

8 GNSS Today GLONASS (May 14, 2007) Partial constellation Operated by the Russian Space Forces Initial Operational Capability in September 1993 but constellation not completed until December weeks (+/- a week) until it started to fall apart Down to 7 satellites on orbit (often only 4 or 5 marked healthy) in 2001 Currently 17 satellites in orbit (as of May 14, 2007) 10 healthy (but not all equally healthy) 6 temporarily switched off (?!?) 1 in commissioning phase (launched December 25, 2006) Reference: Russian Space Agency web site

9 GNSS Today GLONASS (September 18, 2007) Partial constellation Operated by the Russian Space Forces Initial Operational Capability in September 1993 but constellation not completed until December weeks (+/- a week) until it started to fall apart Down to 7 satellites on orbit (often only 4 or 5 marked healthy) in 2001 Currently 17 satellites in orbit (as of September 18, 2007) 6 healthy (but not all equally healthy) 6 temporarily switched off (?!?) 1 in commissioning phase (launched December 25, 2006) 4 in decommissioning phase Reference: Russian Space Agency web site

10 GNSS Today GLONASS Constellation Today (Best-case) Today Credit: R. Zagretdinov, Kazan State University Proton launch failure on September 5, 2007 could delay future launches

11 GNSS Today GPS Levels of Accuracy Code positioning methods Autonomous 1.5 to 10 meters SBAS, CDGPS, DGPS sub-meter to meters Phase positioning methods RT-20, OmniSTAR XP/HP, Starfire decimeter to sub-meter RTK - fixed ambiguity processing centimeter to sub-decimeter (kinematic) sub-centimeter (static and/or post-processed)

12 GNSS - Differential Corrections Many errors in the pseudorange and carrier phase equations are correlated Differencing observations from a satellite between a receiver at a known point (reference station) and a receiver at an unknown point (rover) can drastically reduce errors and increase accuracy. Orbital errors Satellite clock errors Atmospheric errors

13 GNSS Positioning Today - GPS+GLONASS Systems designed to compete Fusion of data possible, but messy Different datums (WGS-84 vs. PZ-90) Different time systems Adds an extra unknown that must be solved for/modeled Different signal separation strategies (CDMA vs. FDMA) Different frequencies Biases induced in GLONASS code measurements due to RF delays Different wavelengths - makes ambiguity resolution more difficult

14 GNSS Positioning - GPS+GLONASS Generally a combined GPS+GLONASS system can improve (when sufficient GLONASS satellites are visible): Solution availability Solution accuracy Ambiguity resolution performance But the integration must be very carefully designed and managed to account for the many significant differences between the two constellations

15 When - GNSS Overview GPS Modernization GLONASS Modernization Galileo Constellation and signal overview Constellation deployment Compass Constellation overview Constellation deployment

16 GPS Modernization - Overview Selective Availability (removed from GPS-III, Sept 18, 2007) Continual improvements to orbit determination L2C L5 Beyond 2013: L1C (GPS-III) (MBOC, Sept 19, 2007) Constellation realignment proposals to transition from 6 planes to 3

17 GPS Modernization Signals Historical Block-IIR-M Block-IIF GPS-III

18 GPS Modernization L2C and L5 Launch Schedules (circa May 2001) L2C L5 Credit: L2/L5 Industry Day May 2001 (

19 GPS Modernization L2C and L5 Launch Schedules (circa 2005)

20 GLONASS Modernization - Overview Directive January 18, 2006 Minimum Operational Capability (18 SVs) by end 2007 Full Operational Capability (24 SVs) by end 2009 Performance comparable with GPS and Galileo by 2010 Directive April 19, 2006 Equipment mass production Mass market

21 GLONASS Modernization - Overview Second civil signal at G2 since GLONASS-M 2003 Third civil signal at G3 starting with GLONASS-K in 2008 Higher reliability and accuracy Integrity information Differential ephemeris and time information Timing improvements Receiving Monitoring Station (RMS) improvements Coordinate system (PZ-90) refinement to ITRF

22 GLONASS Modernization GLONASS-K... FDMA or FDMA+CDMA? GPS-GLONASS Interoperability and Compatibility Working Group National Space-Based Positioning, Navigation and Timing Executive Committee Russian Space Agency both sides noted that concerning the question of the use of FDMA and CDMA, significant progress was made in understanding the benefit to the user Community of using a common approach GLONASS-K may allow addition of CDMA on L1 and the new civil signal

23 Galileo - Overview European Union and European Space Agency Multiple objectives Provide higher precisions than current GPS or GLONASS Improve availability of service at higher latitudes Provide an independent positioning system Primarily for civilian use Designed to compete with yet complement GPS

24 Galileo International Involvement Non-European Participants China (September/October, ,000,000) Israel (July, 2004) Ukraine (June, 2005) India (September, 2005) Morocco and Saudi Arabia (November, 2005) South Korea (January, 2006) Others?!? Argentina, Australia, Brazil, Canada, Chile, Japan, Malaysia, Mexico, Norway, Pakistan, Russia

25 Galileo Levels of Service Open Service (OS) Free of charge, accuracies comparable to GPS Safety of Life (SOL) Free of charge, with integrity messaging Commercial Service (CS) Increased performance, professional users, E6 & open service frequencies, subscription-based Public Regulated Service (PRS) Restricted access, not available for public users

26 Galileo Signal Overview E5a E5b E6 E1 E5

27 Galileo Signal Performance Code Multipath E5a GPS L1 E1 E5 ALTBOC E6 Credit: Simsky, et al, ION GNSS 2006

28 Galileo Constellation Deployment According to ESA (effective May 2005) GIOVE-A and GIOVE-B launched individually First four operational satellites using two launchers into two different orbital planes Galileo validation phase Next two operational satellites into the third plane Remaining satellites for each plane launched via heavy lift vehicle like the Arianne 5 or Proton Multiple satellites (5 to 8) per launch as opposed to GPS (one satellite per launch) or GLONASS (3 satellites per launch) Full operational capability in New estimates in mid-2007 late 2012 to mid-2014

29 Galileo Current Constellation (GIOVE-A) Galileo System Test Bed Version 2 (GSTB-V2) Two experimental satellites Galileo In-Orbit Validation Experiment (GIOVE-A) Launched December 28, 2005 Ranging signals on L1, E5 and E6 (limited to any 2 at a time) GIOVE-B launch still pending Passed preliminary testing Scheduled for late 2007 GIOVE-A2 contract awarded (March 5, 2007) Launch 2 nd half 2008

30 Compass (Beidou) - Overview The People s Republic of China (PRC) National Space Administration Formally announced intentions to increase Beidou from a regional service (geostationary satellites) to a GNSS (combination of geostationary and MEO)

31 Compass Constellation Overview 5 Geostationary satellites to service China 3 GEO satellites launched in 2003, one in 2007 S-band Active positioning 30 Medium Earth Orbiting (MEO) satellites for global coverage 6 orbital planes Similar altitude to GPS and Galileo (20,000 km) Unannounced launch of MEO on April 14, 2007

32 Compass Frequency Plan Overview Filings indicate an intention to overlay: GPS military M-code at L1 and L2 Available on Block-IIR-M and upcoming Block-IIF Galileo PRS (E6) International Telecommunications Union (ITU) Working groups currently assessing potential interference issues with existing GNSS signals or GNSS signal allocations Issue to be discussed at World Radiocommunication Conference 2007 (WRC) set for Geneva, Switzerland in October/November

33 Compass Levels of Service Two levels of service Open/Commercial Service Real-time autonomous positioning 10m Authorized Service Restricted use

34 GPS, Galileo and Compass Signals Credit: Inside GNSS: initial Observations and Analysis of Compass (June 2007)

35 Why Why Is This Important To You? Improved Accuracy Better code measurements Better geometry Improved Availability More satellites in view Less time to initialize Improved Reliability Ambiguity resolution reliability Receiver Autonomous Integrity Monitoring (RAIM), Fault Detection and Exclusion (FDE)

36 GNSS Improved Accuracy Code Measurements (Simulation) Ger Nor Sing

37 GNSS Improved Accuracy Code Position (Simulation) North East Up Ger Credit: Belabbas, et al, ION GNSS 2005 Note: Different scales for each plot!

38 GNSS Improved Accuracy Code Measurements

39 GNSS Improved Accuracy Phase Measurements

40 Improved Accuracy At Longer Baselines Positioning Expectations Manufacturers often include a ppm component to account for the spatial decorrelation of the ionosphere and troposphere with increasing baseline length 1 kilometer -> 1 millimeter 10 kilometers -> 10 millimeters 50 kilometers -> 50 millimeters The more quality measurements you have at different frequencies, the better you can measure/model the atmospheric effect to reduce the ppm component further

41 Improved Geometry (Availability) Urban Canyons Cumulative Percent HDOP

42 Improved Geometry (Availability) Urban Canyons In open skies, GPS+Galileo provides better accuracy, but essentially no improvement in availability In obstructed (low-rise) conditions, GPS+Galileo provides slightly better accuracy and a significant improvement in availability In obstructed (high-rise) conditions, GPS+Galileo provides a significant improvement in accuracy and availability

43 GNSS Effect of Multiple Frequencies on Time To Resolve Ambiguities Credit: Sauer, et al, Trimble, 2004 GPS Credit: Sauer, et al, Trimble, 2004 Galileo

44 GNSS Effect of Multiple Frequencies on Ability To Resolve Ambiguities Correctly GPS Galileo Alberta Geomatics Group Credit: Seminar Sauer, Serieset al, Trimble, 2004

45 Improved Reliability Integrity Monitoring Receiver Autonomous Integrity Monitoring (RAIM) and Fault Detection and Exclusion (FDE) algorithms require an over-determined solution Generally, the more over-determined the better Integrity monitoring inherent with Galileo constellation design Reduced time to detect an anomaly and flag the satellite as unhealthy

46 Challenges To GNSS Manufacturers What to do with all of this. L5 (OS) E5a* (CS, SoL) E5b* M L2C P(Y) PRS CS PRS M C/A OS/GPS III P(Y) G3 B2 G2 B3 B1 G1 L5 ( MHz) E5b ( MHz) L2 ( MHz) E6 ( MHz) L1 ( MHz)

47 Challenges To GNSS Manufacturers - Balance HOW GOOD CAN WE GET? POWER SIZE SIGNALS ACCURACY WHAT IS GOOD ENOUGH? PERFORMANCE WEIGHT COMPLEXITY AVAILABILITY

48 Challenges To GNSS Manufacturers Marketing challenges How do you get the right mix? Who wants/needs what? Performance? Price? Consumer expectation? Emerging technologies? How do you phase in the technology? How good is good enough? Competition s offering? The future of GLONASS? Compass? Galileo? Speed of deployment of GLONASS? Compass? Galileo?

49 Summary GPS and GLONASS undergoing significant modernization efforts Galileo on the verge of deployment Compass a bit of a wild card Modernized and additional signals for all 3 GNSS constellations will increase measurement quality and improve the geometrical strength of the solution Better accuracy Better availability Better reliability

50 Thank you!

51 U.S. & Canada NOVATEL or

52

53 GNSS Today GPS Overview 24 satellites (by design) satellites (actual) Six orbital planes at 55 Ground repeat 23h56m Every 2 orbits Two frequency system L1 ( MHz) C/A and P L2 ( MHz) P and L2C (Block-IIR-M only) Code Division Multiple Access (CDMA)

54 GNSS Today GLONASS Overview 24 satellites (by design) 11+3 satellites (increasing) Three orbital planes at 64.8 Ground repeat 7d23h27.5m Every 17 orbits Two frequency system L1 ( MHz) L2 ( MHz) Credit: Russian Institute of Space Device Engineering Frequency Division Multiple Access (FDMA) Designed to counter GPS

55 GPS and GLONASS Comparison of Range Errors GPS GLONASS m GPS satellite number GLONASS satellite number Credit: S Revnivykh, Deputy Director FSA, September 2006

56 GNSS Positioning - GPS+GLONASS DGPS (Circa 1997) Un/mis-modeled code biases with GLONASS can actually increase error in the computed solution

57 GPS Modernization Selective Availability Selective Availability (SA) set to zero May 2, 2000 SA was the intentional dither of satellite clocks to degrade accuracy of non-differential position solution Errors went from tens of meters to meter-level in a few seconds

58 GPS Modernization Selective Availability

59 GPS Modernization Orbit Determination Additional ground segment infrastructure Better orbital modeling Rule of thumb: Error = URE x DOP URE = User Range Error (m) How good is the signal quality? DOP = Dilution of Precision (dimensionless) How strong is the constellation geometry?

60 GPS Modernization Orbit Determination

61 GPS Modernization L2C Signal Overview Improve accuracy with an easy to track robust signal Second unencrypted civilian signal on L2 ( MHz) A whole new design not just a repeat of the L1 civilian signal First Block-IIR-M launched in September 2005 with signal availability in January 2006 L2C transmission is 2.3dB weaker than L1 C/A L2C has 2.7dB greater data recovery L2C has 0.7dB greater carrier tracking capability Reference: IS-GPS-200D

62 GPS Modernization L5 Signal Overview Third civilian signal at MHz Planned for GPS-IIF launch in 2008 Original launch plan was for L5 starting in 2005 Improved signal structure for enhanced performance Safety of Life Aeronautical Radionavigation Services (ARNS) band

63 GLONASS Modernization Signal In Space Range Error Improvements SISRE, м м м 7 м SISRE, m Time since , days Credit: S Revnivykh, Deputy Director FSA, September 2006

64 GLONASS Modernization Constellation Deployment GLONASS-M GLONASS-K NSV L1 GLONASS GLONASS-M GLONASS-K L1+L2 GLONASS-K L1+L2+L Credit: S Revnivykh, Deputy Director FSA, September 2006

65 Galileo Constellation Description 30 satellites in 3 planes (27 active plus 3 spare) Inclined 56 at an altitude of approximately 23,200 km Ground track repeats every 3 days Satellite design life > 12 years

66 Galileo E1 Signal Overview Overlays GPS L1 E1-B (data channel including unencrypted integrity) E1-C (pilot [dataless] channel) BOC(1,1) Based on 2004 agreement between the US and EU MHz bandwidth Multiplexed BOC (MBOC) Recommended by a technical working group set up under the above agreement Refer to InsideGNSS and GPSWorld for more late breaking information!

67 Galileo E5 Signal Overview E5a and E5b originate from the same modulation (ALTBOC) MHz bandwidth Option to track the signals Non-coherently as two distinct signals Coherently as a combined signal Increased code tracking accuracy Needs an extra-wide front-end filter, making this technique more suited to medium- to high-end systems More processing power equates to greater power consumption

68 Galileo E5 Signal Overview (continued) E5a E5b Data channel and pilot (dataless) channel Unencrypted ranging and data codes to support navigation and timing 25 bps data rate for robust data demodulation Data channel and pilot (dataless) channel Unencrypted ranging and data codes to support navigation and timing Unencrypted integrity and encrypted commercial data 125 bps data rate

69 Galileo E6 Signal Overview Commercial access signal MHz bandwidth Encrypted ranging and data 500 bps Major issue to be resolved How do you administer the commercial aspect of this signal? Difficult for GNSS manufacturers to properly assess E6 until this issue is resolved.

70 Multiple Carrier Instantaneous Ambiguity Resolution Nines(p) = -log 10 (1-p) P = 2 nines (99%) P = 0.02 nines (5%) GPS or Galileo 2f given 4cm (std dev) of ionosphere effect, what is the probability of being able to resolve the ambiguities instantaneously?

71 GNSS Improved Availability Reduction in Ambiguity Resolution Failure Rates 100 Failure Rate (%) Credit: Sauer, et al, Trimble, 2004 for this study and at a 50km baseline the ambiguity resolution failure rate is approximately 6% for GPS, 2% for Galileo and.04% for GPS+Galileo