Supporting Earth Sciences: The Global Geodetic Observing System (GGOS) Ruth Neilan

2008 Bi-Lateral Workshop - China-US Earthquake Studies Protocol Nov 11-14 GG S

Supporting Earth Sciences:The Global Geodetic Observing System (GGOS)

Ruth Neilan

Director, International GNSS Service Central BureauNASA/Jet Propulsion Laboratory (JPL)/California Institute of Technology

http://www.ggos.org http://igs.org

US-China WorkshopBoulder, Colorado

November 14, 2008

GG S


Overview

• Global Geodetic Observing System (GGOS)

• IGS Update Data and Products

• Challenges

– Information and Data - ICSU, IUGG, GEOSS

– GNSS System Advances

– International Committee on GNSS

• Summary and Outlook


Motivation

Helplessness in the face of natural disasters demonstrates that our knowledge of the Earth’s

complex system is rather limited.


Motivation: Monitoring the Earth System


Motivation• Helplessness in the face of natural disasters demonstrates that our

knowledge of the Earth’s complex system is rather limited.

• Deeper insight into the processes and interactions within this system is one of the most urgent challenges for our society.

• To monitor changes in the Earth system and the processes causing natural disasters a Global Earth Observing System (GEOSS) is being established.

• GGOS = geodesy’s contribution to GEOSS; GGOS as metrological basis for all monitoring: provides the global reference frame.

• Space geodetic techniques (VLBI, SLR/LLR, GNSS, DORIS), altimetry, InSAR, gravity missions, in-situ measurements, etc. allow the monitoring of the Earth system with an unprecedented accuracy (10-9)


GGOS: Monitoring and Modeling the Earth‘s System

Measuring Information about Earth System

Influence / ModellingObservation Modelling

Space Geodetic

Techniques

VLBISLR/LLR

GNSSDORIS

AltimetryInSAR

Gravity Satel.

Terrestrial Techniques

LevellingAbs./Rel.

GravimetryTide Gauges

Air-/Shipborne

Geometry

Station Position/Motion,

Sea Level Change,Deformation

Earth Rotation

Precession/Nutation,

Polar Motion,

UT1, LOD

Gravity

Geocenter

Gravity field,

Temporal variations

Earth System

Sun/Moon

(Planets)

Atmosphere

Ocean

Hydrosphere

Cryosphere

Core

Mantle

Crust

COMBINATION

INTE RACTIONS

Terrestrial reference frame: high accuracy and long-term stability


IAG Services: Backbone of GGOS

IERS: Intern’l Earth Rotation and Reference Systems Service

IGS: International GNSS Service

IVS: International VLBI Service

ILRS: International Laser Ranging Service

IDS: International DORIS Service

IGFS: International Gravity Field Service

BGI: Bureau Gravimetrique International

IGeS: International Geoid Service

ICET: International Center for Earth Tides

ICGEM: International Center for Global Earth Models

PSMSL: Permanent Service for Mean Sea Level

IAS: International Altimetry Service (in preparation)

BIPM: Bureau International des Poids et Mesures

IBS: IAG Bibliographic Service

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Std


Space Geodetic Techniques

GPS

GLONASS

GALILEO

DORIS

VLBI SLR/LLR Altimetry InSAR

COMPASS


GGOS: the Ground-Based Component

VLBI

Abs.Grav.

Sup.Grav.

GPS

SLR/LLR

GPS/GLONASS

DORIS


GGOS: the Satellite Mission ComponentCHAMP

GRACE

GOCE

COSMIC

TerraSAR-X

SWARM

JASON-1

TanDEM-X

International GNSS ServiceFormerly the International GPS Service

Graph courtesy Analysis Coordinator

G. Gendt, GFZ Potsdam

GPS Applications in IGS Projects & Working GroupsIGS Reference Frame

Supporting AREF - African Reference FramesPrecise Time & Frequency Transfer

GLONASS Pilot Service Project, now routine within IGS processesLow Earth Orbiters Project

Ionosphere WGAtmosphere WG

Sea Level - TIGA ProjectReal-Time ProjectData Center WG

GNSS WG

GNSS: Global Navigation Satellite System

The IGS is a voluntary federation of more than 200 worldwide agencies in more than 90 countries that pool resources and permanent GPS station data to generate precise GPS products.

Over 350 permanent tracking stations operated by more than 100 worldwide agencies comprise the IGS network. Currently the IGS supports two GNSS: GPS

and the Russian GLONASS.

IGS products are formed by combining independent results from each of several Analysis Centers. Improvements in signals and computations have brought the centers’ consistency in the Final GPS satellite orbit calculation to ~ 2cm

http://igscb.jpl.nasa.govNASA funds the coordinating center the IGS Central Bureau

http://igscb.jpl.nasa.gov/









Global Plate Motion


Ilk et al. (2005) Mass Transport and Mass Distribution in the Earth System, 2nd Edition, SPP1257 DFG

Gravity Field, Mass Transport


Combination / Integration

• Ensure the consistency and improve the accuracy of the resulting geodetic products

• Complementary use of the individual techniques to strengthen the solutions

• Benefits from observing instruments co-located at the same site/satellite

• Distinguish genuine geodetic/geo-physical signals from technique-specific systematic biases

• Crucial to achieve separation between different components and processes in the Earth System (e.g. mass transport)


Data and data policy, national policies and global science• International Council for Science, Strategic Committee on Information

and Data– to facilitate a new, coordinated global approach to scientific data and

information that ensures equitable access to quality data and information for research, education and informed decision-making

• International Union of Geodesy and Geophysics establishing– Inter-Union Committee on Data and Information

• GEO System of Systems - GEOSS– Approach to data sharing principles– http://www.earthobservations.org/geoss_dsp.shtml

GNSS Evolution• GPS modernization - new signals, GLONASS improvements

– Smooth transition, calibration, validation for continued long-term, quality observations

• Incorporating, integrating New GNSSs:– China’s COMPAS, EU GALILEO - interoperabilty? Interchangeability– Regional systems - Japan’s QZSS and India’s GAGAN - GPS-like signals

Challenges


International Committee on GNSS (ICG)• Committee on Peaceful Uses of Outer Space (COPUOS) - United

Nations Office of Outer Space Affairs (UN-OOSA)– Forum for multi-lateral discussions– …promote cooperation, as appropriate, on matters of mutual interest

related to civilian satellite-based positioning, navigation, timing and value-added services, as well as the compatibility and interoperability of global navigation satellite systems, while increasing their use to support sustainable development, particularly in developing countries

– ICG Participants are system providers, international governmental organizations and international non-governmental organizations

– Opportunity for users - and high end scientific user community - to interact with system providers

Challenges, cont.


PRESS RELEASE—DRAFTThursday 23 October 2008, 18.00

Global Science community agrees on first steps to establish a global virtual system for scientific dataScientific organisations representing over one hundred and thirty countries agree to overhaul existing world data centres and services to create a World Data System

Maputo, Mozambique—the existing networks for collecting, storing and distributing data in many areas of science are inadequate and not designed to enable the inter-disciplinary research that is necessary to meet major global challenges. These networks must be transformed into a new inter-operable data system and extended around the world and across all areas of science. The General Assembly of the International Council for Science (ICSU) agreed today to take the first strategic steps to establish such a system.

More scientific data and information is now available than at any other time in history and the volume is increasing daily, particularly via the World Wide Web. Yet the quality, long-term stewardship and availability of this data is largely uncertain and a large amount of valuable scientific data remains inaccessible. Over 50 years ago, ICSU established networks of data centres and services to provide full and open access to scientific data and products for the global community. But the world has changed enormously in 50 years, most notably with advances in technology, and it is time for the existing structures to be integrated into a new expanded system—a World Data System.

The expert report recommending the new system and presented to the ICSU General Assembly asserts: ‘there is a need for global federations of professional state of the art data management institutions, working together and exchanging practices. Such federations can provide quality assurance and promote data publishing, providing the backbone for a global virtual library for scientific data’. The report concludes that ICSU itself can play a leading role by re-structuring its own data bodies.

Ray Harris, chair of the expert Committee that produced the report said, ‘Data is the lifeblood of science and there are many exciting developments, which means that access to scientific data both for science and for policy making should be much easier. However, in many areas there is little order and the origin and reliability of what one finds on the web can be almost impossible to determine’.

‘A more strategic and systematic international approach, together with significant financial investment at the national level, is urgently required if we are to realise the full benefit of science for society,’ Harris continued.


Dave Carlson, the Director of the programme office for the International Polar Year (IPY)—a major, ICSU-sponsored, interdisciplinary research programme that is using and generating enormous amounts of data—added: ‘There are more than 200 IPY research projects, funded to the tune of 1.5 billion Euros, and its major legacy should be the data that will inform polar research for years to come. But we still don’t know how most of this data will be handled’.

‘The new ICSU World Data System should help provide at least part of the answer. A little bit of extra resource for data management is urgently needed to ensure maximum return on what has been a huge public investment in IPY.’

ICSU will be implementing the recommendations in the report over the next three years. The report is available at: http://www.icsu.org/Gestion/img/ICSU_DOC_DOWNLOAD/2123_DD_FILE_SCID_Report.pdf

Media enquiriesJacinta Legg, Science Communications Officer, ICSU. [email protected], Tel: +33 1 45255777. For journalists at the General Assembly, contact: Gisbert Glaser, Tel: +33 6 32310027.

About ICSUFounded in 1931, ICSU is a non-governmental organization with a global membership of national scientific bodies (114 Members, representing 134 countries) and International Scientific Unions (29 Members). The Council is frequently called upon to speak on behalf of the global scientific community and to act as an advisor in matters ranging from the environment to conduct in science. ICSU’s activities focus on three areas: planning and coordinating research; science for policy; and strengthening the Universality of Science.


• GGOS– Support of Earth system science is fundamental driving principle– Provides a framework for multi-disciplinary investigations to

address critical scientific issues in coming decades– Maintains, evolves and extends the precise reference frame to

relate all observations

• Long-term stewardship of data, information and data analysis products is key objective– Long-term geodetic time series

• Bridging digital divide with developing countries and pacing science and technical developments

Summary & Outlook


Some Weblinks

• http://www.ngs.noaa.gov/IGSWorkshop2008/

• http://sidt.gpsworld.com/gpssidt/Expert+Advice+%26+Leadership+Talks/Expert-Advice-Reference-Frame-for-Africa/ArticleStandard/Article/detail/545022


Backup Slides


Global Geodetic Observing System (GGOS)

U S E R S

G G O S Steering Committee Science Panel Executive Committee Secretariat

RegionalAssociations

European Combined Geodynamic Network

Nordic Geodetic Observing System

IAG Commissions 1: Reference Frames 2: Gravity Field 3: Earth Rotation & Geodyn. 4: Positioning & Applications

GGOS Working Groups

Networks & Communications Data & Information Missions Conventions, Analysis Outreach

IAG Services IGS, IVS, ILRS, IDS, IERS IGFS, IGeS, BGI, GGP PSMSL, IAS, BIPM, IBS

GEO and GEOSSGGOS Contribution to GEO Plenary GEO Committees &

WGs GEO Work plan tasks

IGOS-P Contributions to

existing Themes New Theme:

„Earth System Dynamics“

Scientific &tech. innovation

Regional implementation

Societalrelevance

Integration

Strategy & planning

Infrastructure, service, products


Rotation of theEarth

Deformation of theEarth

Tidesof the

solid EarthLunisolar

Gravitationalacceleration

Atmospherictides

Atmosphericloading

Density variations

in theatmosphere

Global vegetation

Global ground water

Oceanictides

Ocean currents

Angular momentum

variationof the

atmosphere

Angular momentum

variationof the

oceans

Oceanloading

Effects from

Earth interior

Snow

Postglacialland uplift

…

Tectonicplate motion

Volcanism

EarthquakesPole tides

Angulartorques

Gravity Field of theEarth

Model of the Interactions in the Earth System

Documents

Supporting Earth Sciences: The Global Geodetic Observing System (GGOS) Ruth Neilan