The future of gnss for space weather monitoring and research
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The Future of GNSS for Space Weather Monitoring and Research. Patricia H. Doherty Institute for Scientific Research Boston College. Expert Meeting on Improving Space Weather Forecasting in the Next Decade Vienna, Austria 10 February 2014. Outline. Historical perspective (before GPS)

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The future of gnss for space weather monitoring and research

The Future of GNSS for Space Weather Monitoring and Research

Patricia H. Doherty

Institute for Scientific Research

Boston College

Expert Meeting on Improving Space Weather Forecasting in the Next Decade

Vienna, Austria 10 February 2014


Outline

Outline

  • Historical perspective (before GPS)

  • Research capabilities with GPS

  • Perils of GPS

  • Future Improvements

    • Multi-constellations

    • Multi-frequencies

    • New signals

  • What lies ahead…


The future of gnss for space weather monitoring and research

Historical Measurements

Geomagnetic Storm of March 1989

Single point measurements from faraday rotation of signals from geostationary satellites


The future of gnss for space weather monitoring and research

Measurements of Halloween 2003 Storm

Distributed networks of sensors yield global physics unattainable with single-point measurements

Example :

Global GPS-derived

ionospheric mapping

during geomagnetic

disturbances

[Coster et al, 2003]


The future of gnss for space weather monitoring and research

Monitoring Low-latitude Ionosphere

LISN


The future of gnss for space weather monitoring and research

GPS Satellite Signals for Space Weather Monitoring/Research – not without problems

Horizontal DGPS and WAAS Position Errors

Halloween Storms 2003

  • Space Weather has impacts on GPS:

    • Reduced accuracy - position errors due to large gradients

    • Reduced availability and continuity due to loss of lock, cycle slips and scintillation

    • Reduced integrity?

S. Skone, 2012


The future of gnss for space weather monitoring and research

GPS Satellite Signals for Space Weather Monitoring/Research – not without problems

Ascension Island (7.98S, 345.59E)

16 Mar 2002

  • Space Weather has impacts on GPS:

    • Reduced accuracy - position errors due to large gradients

    • Reduced availability and continuity due to loss of lock, cycle slips and scintillation

    • Reduced integrity?


New satellite systems and signals are on the way

GREAT NEWS!

New Satellite Systems and Signals are on the way

  • Should Enable Improved:

    • Accuracy

    • Availability (with improved interference rejection)

    • Integrity

    • Continuity

GPS Block III Satellite -Source: Lockheed-Martin.


Gnss systems compatible and interoperable

Galileo (EU)

GLONASS

Beidou/COMPASS (China)

GNSS Systems - Compatible and Interoperable

Global Positioning System (GPS)


Gnss constellations

GNSS Constellations

  • Global Positioning System (GPS)

  • GLObal'nayaNAvigatsionnayaSputnikovayaSistema (GLONASS)

  • GALILEO

  • BeiDou/COMPASS

  • Quasi-Zenith Satellite System (QZSS)

  • Indian Regional Navigation Satellite System (IRNSS)

  • Satellite-based Augmentation System (SBAS)


Global positioning system gps

Global Positioning System (GPS)

  • U.S. satellite navigation system

    • Program began in early 1970’s

    • First launch in 1978

    • Declared fully operational in 1995

  • Nominal 24-satellite constellation

    • ~20,200 km altitude

    • 55 degree inclination

    • 6 orbital planes

    • Now 31 operational satellites

GPS Block IIR-M Satellite

Source: Lockheed-Martin.


The future of gnss for space weather monitoring and research

Col. Bill Cooley, GPS Directorate, ION GNSS 2013


Gps signal evolution

GPS Signal Evolution

L5

L2

L1

C/A

P(Y)

P(Y)

Legacy Signals

L1C

C/A

L2C

Signals After

Modernization

M

M

P(Y)

P(Y)

1176.45 MHz

1227.6 MHz

1575.42 MHz

C. Hegarty, MITRE, May 2013


Glonass global naya navigatsionnaya sputnikovaya sistema

GLONASSGLObal'nayaNAvigatsionnayaSputnikovayaSistema

  • Russian satellite navigation system

    • First launch in 1982

  • Nominal 24-satellite constellation

    • 19,100 km altitude, 3 planes

    • Fully populated in 1995…

    • …but then deteriorated to as low as 7

  • Now fully replenished – 24 operational satellites milestone reached in December 2011

  • Next Generation

    • 4 new civil signals

    • 2 new frequencies

Source: Russian Federation.


Galileo

GALILEO

  • European contribution to the GNSS

    • Jointly managed by European Commission (EC) and European Space Agency (ESA)

    • Program gained significant boost in March 2002 with release of ~$1.1B euro

  • 30 satellite constellation

    • 3-planes

    • 56 deg inclination

    • ~23,200 km altitude

  • Two test satellites launched in 2005, 2008

    • No longer operating

  • In-orbit validation (IOV) satellites: Oct 2011 (2), Oct 2012 (2)

  • Expecting Full Operational Capability in 2018

Source: European Space Agency.


Beidou compass

BeiDou (COMPASS)

  • Chinese satellite navigation system

  • Final constellation planned to include:

    • 27 satellites in medium Earth orbit (MEO)

      • 55 degree inclination, ~21,500 km altitude

    • 5 satellites in geostationary orbit (GEO)

    • 3 - 5 satellites in inclined geosynchronous orbit (IGSO)

  • Launches:

    • Four experimental GEOs: 2000 (2), 2003, 2007

    • MEOs: 2007, 2012 (4)

    • GEOs: 2009, 2010 (3), 2012 (2)

    • IGSOs: 2010 (2), 2011 (3)

  • Providing regional service in Dec 2012 (BeiDou)

  • Global Coverage ~2020 (COMPASS)


Quasi zenith satellite system qzss

Quasi Zenith Satellite System (QZSS)

Asian and Pacific Region

  • Japanese system

  • Plan calls for four satellites initially

    • Three highly elliptical ~36,000 km altitude orbits

    • One geostationary

    • Eventual growth to 7 satellites (design to-be-determined)

  • First satellite launched September 2010 (Michibiki)

  • 4 satellite system operational in 2018

Source: Japan Aerospace Exploration Agency.


Indian regional navigation satellite system irnss

Indian Regional Navigation Satellite System (IRNSS)

  • Indian regional system

  • Final constellation planned to include:

    • 3 satellites in geostationary orbit (GEO)

    • 4 satellites in inclined GSO

  • First Geo launched in July 2013

  • Full implementation in 2016

Source: Indian Space Research Organization.


The future of gnss for space weather monitoring and research

TheFAA Wide Area Augmentation System (WAAS)

Designed to improve GPS accuracy, availability and integrity.

  • Current Infrastructure:

  • 38 Reference Stations

  • 3 Master Stations

  • 6Uplink stations

  • 3 Geostationary Satellites

Courtesy of the FAA

  • WAAS message provides:

  • corrections for satellite orbits, time and the ionosphere

  • estimates of the uncertainty of those corrections

  • Future primary means of civil air navigation

  • For all aircraft in all phases of flight

    • Non-Precision Approach (NPA) – en-route

    • Vertically Guided Approach (LPV) – runway

  • First of many worldwide systems


Waas coverage

WAAS Coverage


Other satellite based augmentation systems sbas

Other Satellite-based Augmentation Systems (SBAS)

  • Europe: European Geostationary Navigation Overlay Service (EGNOS)

    • Operational - three satellites

  • Japan: Multifunctional Transport Satellite (MTSAT)-based Augmentation System (MSAS)

    • Operational - two satellites

  • India: GPS and GEO Augmented Navigation (GAGAN)

    • Not yet operational - 2 satellites in orbit

  • Russia: System of Differential Correction and Monitoring (SDCM)

    • Not yet operational - 1 satellite in orbit


Current and future satellites

Current and Future Satellites

  • GNSS now includes 87 satellites (plus associated ground networks)

  • More than 150 satellites anticipated within a decade

C. Hegarty, MITRE, May 2013


Gnss signal evolution

GNSS Signal Evolution

L1

L5

L2

GPS

(US)

Future

CDMA signal

GLONASS

(Russia)

Galileo

(Europe)

COMPASS

(China)

IRNSS

(India)

QZSS

(Japan)

SBAS

(US Europe India Japan)

Compass & IRNSS

In S-band

23

C. Hegarty, MITRE, May 2013


The future of gnss for space weather monitoring and research

Future of GNSS for Space Weather Research

  • Multi-constellation/Multi-frequency GNSS

    • Improves performance

    • Operational benefits (safety in applications)

    • Reduced loss of service

    • Increased coverage area

    • Range delay errors will essentially disappear once dual-frequency signals are available to civil users

    • Scintillation is not going away……

      • Although frequency diversification may be very effective

      • L5 (1176.45 MHz) should be somewhat more sensitive to scintillation than L1 (1575.MHz), but the signal will be stronger than L1

  • Building robustness in receiver design is most important

  • Education, equipment and measurements are needed for research and applications


Summary

Summary

We’ve come a long way in space weather research with GNSS.

Great things yet to come!

Courtesy, P. Enge


The future of gnss for space weather monitoring and research

Thank you for your attention!

Patricia H. Doherty

[email protected]

Phone: 617-552-8767

Fax: 617-552-2818

http://www.bc.edu/isr


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