global geodetic observing system (ggos): status and future

AOGS 5th Annual Meeting 2008, June 16-20, 2008, Busan, Korea GG S

Global Geodetic Observing System (GGOS):Status and Future

Markus Rothacher, Ruth Neilan, Hans-Peter Plag

GeoForschungsZentrum Potsdam (GFZ)Jet Propulsion Laboratory (JPL)

University of Nevada, Reno (UNR)

AOGS 5th Annual Meeting 2008June 16-20, 2008

Busan, Korea

GG S 2020


• Motivation

• Monitoring and Modeling the Earth System

• Structure of GGOS

• GGOS Instrumentation / Infrastructure

• GGOS Data Flow and Portal

• Processing, Analysis, Combination

• Modeling and Interpretation

• Conclusions

Contents


Motivation: Missing Understanding of Key Processes


Global Monitoring Information about Earth System

InterpretationInnovative Technologies

Space Techniques

VLBISLR/LLR

GNSSDORIS

AltimetryInSAR

Gravity/Magnet. Missions

Terrestrial Techniques

LevellingGravimetry

Tide Gauges

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

Crust

Mantle

Core

COMBINATIONS

INTE RACTIONS

GGOS: Monitoring and Modelling the Earth‘s System

Reference frames: highest accuracy and long-term stability


GGOS Chronology

• July 2003: Decision of the International Association of Geodesy (IAG) to establish a Global Geodetic Observing System (GGOS)

• April 2004: IAG/GGOS becomes participating organization of GEO (Group on Earth Observation) for the realization of GEOSS (Global Earth Observing System of Systems)

• May 2006: GGOS becomes official member of IGOS-P (Integrated Global Observation Strategy Partnership)

• July 2007: GGOS becomes an official component of the IAG, the observing system of the IAG

• GGOS2020 reference document is almost complete, is in the review process (~ 200 pages)


IAG Services: Backbone of GGOS

IERS: International 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

IDEMS: International Digital Elevation Models Service

PSMSL: Permanent Service for Mean Sea Level

IAS: International Altimetry Service (in preparation)

BIPM: Bureau International des Poids et Mesures

IBS: IAG Bibliographic Service

Ge

om

etr

yG

rav

ime

try

Oc

ean

Std


Coordination Office

Bureau for Networks and Communication

Bureau for Satellite and Space Missions

Bureau for Conventions and Standards

Regional and Global Data and Product Centers

Archiving and Dissemination

Global Networks of Observing Stations

Earth Observation Satellites / Planetary Missions

Mission-specific Data and Product Centers

Archiving and Dissemination

Data Analysis Centers

Combination Centers

Modeling Centers

Users, Science & Society

GGOS Portal

Access to all information, data,

products

Meta data; information Real data; information

Structure of the Future GGOS


GGOS Instrumentation: 5 Levels of Objects

5:

Level 4:Moon,Planets Moon

Planets


VLBI

Tide GaugesSLR/LLR

GPS

DORIS

Sup.Grav.

Abs.Grav.

Level 1: Ground-Based Component


Future Core Ground-Based Infrastructure

Core Network (~ 40 Stations):• 2-3 VLBI telescopes for continuous observations

• SLR/LLR telescope for tracking of all major satellites

• At least 3 GNSS antennas and receivers (controlled equipment changes)

• DORIS beacon of the most recent generation

• Ultra-stable oscillator for time and frequency keeping and transfer

• Terrestrial survey instruments for permanent/automated local tie monitoring

• Superconducting and absolute gravimeter (gravity missions, geocenter)

• Meteorological sensors (pressure, temperature, humidity)

• Seismometer for combination with deformation from space geodesy and GNSS seismology

• Additional sensors: water vapor radiometer, tilt-meters, gyroscopes, ground water sensors, …

General Characteristics: highly automated, 24-hour/365 days, latest technologies


Ground-Based Infrastructure: Innovation

Galileo Experimental Sensor Station (GESS)

VLBI Twin Telescope (Wettzell)

VLBI:• High slew rates (> 5 deg/s)• 1-3 small telescopes at a site• Continuous frequency range

(2-18 GHz)

GNSS:• GPS, Glonass, Galileo,

Compass, … • Sampling > 10 Hz• Real-time• 3 antennas/receivers

SLR:• kHz laser technology• 2 frequency systems• Higher quantum efficiency

DORIS:• 3rd generation DORIS

systems

kHz Laser: Lageos Spin (Graz)

DORIS Beacon (Thule)


Level 2: Satellite Mission Component

CHAMP GRACE GOCE

COSMIC

TerraSAR-X

SWARM

JASON-1 TanDEM-X

GRACE Follow-on ?

…

Topex/Pos. JASON-2

CHAMP

…

…

CHAMP

…

MetOp

IceSat-2IceSat-1 Cryosat-2

…

…

… and new mission concepts

Gravity Field

Ice Altimetry

Atmosphere

Ocean Altimetry

Earth Surface

Magnetic Field


New Mission Concepts: Constellations and Formations

Formation flying, swarms

Satellite Constellations


Future satellite constellation as a component of a Multi-Hazard Early Warning System ?

New Mission Concepts: GNSS Reflectometry


RO Antenna POD Antenna Star Sensors SLR Retro-Reflector VLBI Sender

3 GPS Receiver Board (Redundancy)

Micro- Satellite

New Mission Concepts: Co-location Micro-Satellite(s)


Level 3, 4, 5: GNSS + Extraterrestrial

GNSS and SLR Satellites:

• More than 100 GNSS satellites in 2020: GPS (24/32) , GLONASS (24/19), GALILEO (30/1), QZSS (3/0), COMPASS (30/4), …

• Cheap LAGEOS-type satellites with laser retro-reflectors and with GNSS receivers forming a network in space with internally 1 mm accuracy (distances up to 14’000 km)

Geodetic Planetary Missions:

• Bepi Colombo, Mars missions, lunar exploration (GRAIL, LEO), …

Stars (observed with CCD cameras or in future with GAIA)

Quasars


GGOS Data Flow and Portal

Network Synergies:

• Common data communication and infrastructure for all techniques (archiving, …)

• Real-time data transfer

• New communication technologies for remote areas


Processing, Analysis, Combination

Processing and Analysis:

• Fully automated processing in near real-time or even in real-time (early warning systems, GNSS seismology, atmosphere sounding, …)

• Full reprocessing capabilities for all data available, long consistent time series for long-term trends

• Combination of all data types on the observation level

• Combination with LEO data (co-location, gravity, geocenter, atmosphere, …)

• Combination with satellite altimetry data (and with InSAR ?)

• Combination with terrestrial data (e.g. gravity field, …)

• Combination of different analysis centers (redundancy, reliability, accuracy, …)

Improvements in modeling, parameterization, conventionsSupercomputers, visualization


Combination: Tsunami Early Warning System

GNSS receivers


Combination of GNSS / Seismology

• Earth`s motion during the earthquake combination with seismometers• Deformation due to the earthquake (magnitude determination, rupture process)

He

igh

t [m

]

E

ast

[m

]

N

ort

h [

m]

Sumatra Earthquake of September 12, 2007


Tsunami Buoy: GPS / OBPU / Seismometer


Filtered GPS HeightsOcean Bottom PressureOcean Tidal Model (GOTT)

Tsunami Buoy: Sea Level Height

RMS: ~ 2-3 cmTsunami: ~ 50 cm


Combination of Geometry and Gravity (IERS/IGFS)

GEOMETRYGPS, Altimetry,

INSARRemote Sensing

LevelingSea Level

EARTH ROTATION

VLBI, SLR, LLR,GPS, DORIS

Classical: AstronomyNew: Ringlasers, Gyros

GRAVITY FIELD

Orbit AnalysisSatellite Gradiometry

Ship-& Airborne GravimetryAbsolute Gravimetry

Gravity Field Determination

REFERENCE SYSTEMS

VLBI, SLR, LLR,GPS, DORIS

IERS

IGFS

Physical heights, geoid

Ellipsoidal heights


Orientation of theEarth

Precession,NutationPolar motionLength of day

Deformation of theEarth

Tidesof the

solid EarthLunisolar

Gravitationalacceleration

Atmospherictides

Atmosphericloading

Global vegetation

Global ground water

Oceanictides

Ocean circulation

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

Density variations

in theatmosphere

Earth System Modelling


Example: Sea-Level Change & Ice-Mass Balances

Glacial-isostatic adjustment

Altimetry missions

Envisat Jason-1

ICESat CryoSat II

Gravimetry missions

GRACE

Terrestrial networks

Tide gauge GPS

Ocean modeling

Sea-level change (mm/a)

Data processing

Geodynamic modeling

Geoid change (mm/a)


• Geodesy can contribute significantly to the monitoring and understanding of the Earth system

• Integration of a multitude of different and innovative sensors on the ground and in space into a GGOS

• Complete and consistent data processing chains ranging from the acquisition to the processing of vast amounts of observational data

• Combination and assimilation of the geodetic/geophyiscal parameters into complex numerical models of the Earth system

• This will finally allow the understanding and prediction of the processes in the Earth system for the benefit of human society.

Conclusions


Thank you for your attention !

global geodetic observing system (ggos): status and future

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