The satellite -only global gravity field model GOCO02S€¦ · gravity field model GOCO02S Helmut...

TheThe satellitesatellite--onlyonly globalglobal

gravitygravity fieldfield modelmodel GOCO02SGOCO02S

Helmut Goiginger, Daniel Rieser, Torsten Mayer-Guerr

Institute of Theoretical Geodesy and Satellite Geodesy, TU Graz

Roland Pail, Thomas Fecher, Thomas Gruber, Alberta Albertella

Institute of Astronomical and Physical Geodesy, TU München

Andrea Maier, Eduard Höck, Sandro Krauss, Walter Hausleitner, Oliver Baur

Space Research Institute, Austrian Academy of Sciences

Adrian Jäggi, Ulrich Meyer

Astronomical Institute of University of Bern

Jan Martin Brockmann, Wolf-Dieter Schuh , Ina Krasbutter, Jürgen Kusche

Institute of Geodesy and Geoinformation, University of Bonn

2

EGU General Assembly Vienna, 04.04.2011 GOCO Consortium

The satellite-only global gravity field model GOCO02S

ObjectivesObjectives and and PrinciplesPrinciples

� Parametrization of model: spherical harmonic series expansion

� Basic equation: combination of consistent normal equation systems

� Optimum solution: variance component estimation

( ) ( ) ( ) ( )[ ]λλϑλϑ mSmCPr

R

R

GMrV

lmlm

l

m

lm

ll

l

sincoscos,,0

1

0

max

+

= ∑∑

=

+

=

( ) ( )......2121

++=++ nnxNN

( ) ( )......22112211

++=++ nwnwxNwNw

3



Data SetsData Sets

Data setGOCO01S

d/o 224

GOCO02S

d/o 250

GOCO02S

#obs. [Mio.]

ITG-Grace2010sd/o 180

7 years

d/o 180

7 years85

GOCE SGG

Satellite gravity gradients

d/o 224

2 months

d/o 250

8 months57

GOCE SST-hl

Sat.-to-sat. tracking in high-low

d/o 110

12 months72

CHAMPd/o 120

8 years63

SLRd/o 5

5 years, 5 sat.2

Kaula Regularization d/o 170-224 d/o 180-250

280

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GOCE SGG GOCE SGG datadata setset

� gradient analysis:

– determination of observation segments

– outlier detection

– noise handling: estimation of individual filters for realistic stochastic

modelling

� Full normal equation system up to d/o 250 without the use of anyprior gravity information

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GOCE SGG GOCE SGG datadata setsetE

rror

[mE

/sqrt

(Hz)]

zzV

IndividualIndividual contributionscontributions

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Individual contributionIndividual contribution

Contribution to

(near-)sectorial coefficients

8



Individual contributionIndividual contribution

� GRACE: dominant up to 120

� GOCE: dominant from 140-220

� Regularization: dominant from 230-250

� very smooth transistions

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Individual contributionIndividual contributionDegree variances of error estimatesDegree variances of error estimates

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Cumulative Cumulative geoidgeoid height error height error

estimatesestimatesC

um

ula

tive

ge

oid

he

igh

t e

rro

rs [m

]

11



GeoidGeoid height deviations [m] EGM2008 height deviations [m] EGM2008 –– GOCO01S up to GOCO01S up to d/od/o 180180

12



GeoidGeoid height deviations [m] EGM2008 height deviations [m] EGM2008 –– GOCO02S up to GOCO02S up to d/od/o 180180

13



CovarianceCovariance propagationpropagation to to geoidgeoid heightheight errorserrors [m] up to d/o 180[m] up to d/o 180

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SurfaceSurface velocitiesvelocities [m/s] [m/s] derivedderived fromfrom MDT (up to d/o 180)MDT (up to d/o 180)

ITG-Grace2010s

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GOCO01S

16




GOCO02S

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RMS of RMS of geoidgeoid heightheight differencesdifferences betweenbetween gravitygravity fieldfield modelsmodels and and

GPSGPS--levelingleveling observationsobservations

11,611,634,913,311,5837Japan

4,46,726,314,26,8675Germany

14,015,730,317,315,4430Canada

d/o 200

10,610,310,510,310,2837Japan

3,54,44,64,54,5675Germany

14,014,514,714,314,4430Canada

d/o 150

10,210,310,210,310,3837Japan

3,83,73,93,93,8675Germany

14,314,414,614,414,4430Canada

d/o 100

σN [cm]

EIGEN-51CTIM2*ITG-Grace2010sGOCO01SGOCO02S#points

*ESA GOCE-only model based on time-wise approach

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SummarySummary and Outlookand Outlook

� major improvements in areas where only a few and less accurate terrestrial

measurements are available

� continuously increasing availability of GOCE and GRACE data

� further improvements due to extended GOCE mission can be assured

� inclusion of terrestrial data � work in progress

� Project webpage & Downloads (within upcoming weeks)

http://www.itsg.tugraz.at/goco

� International Centre for Global Earth Models webpage:

http://icgem.gfz-potsdam.de/ICGEM

The satellite -only global gravity field model GOCO02S€¦ · gravity field model GOCO02S Helmut...

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