T FIRST INDEPENDENT LUNAR GRAVITY FIELD SOLUTION IN THE AC.AT FIRST INDEPENDENT LUNAR GRAVITY FIELD SOLUTION IN THE FRAMEWORK OF PROJECT GRAZIL OEAW.A FRAMEWORK OF PROJECT GRAZIL W.IWF.O Harald Wirnsberger 1 , Sandro Krauss 1 , Beate Klinger 2 , Torsten Mayer-Gürr 2 WWW 1 Space Research Institute, Austrian Academy of Sciences; 2 Institute of Geodesy, Graz University of Technology The twin satellite mission Gravity Recovery and Interior Laboratory (GRAIL) aims to recovering the lunar gravity field by means of intersatellite Ka-band ranging (KBR) observations. In order to exploit the potential of KBR data, absolute position information of the two probes is required. Hitherto, the Graz ranging (KBR) observations. In order to exploit the potential of KBR data, absolute position information of the two probes is required. Hitherto, the Graz lunar gravity field models (GrazLGM) relies on the official orbit products provided by NASA. In this contribution, we present for the first time a completely independent Graz lunar gravity field model to spherical harmonic degree and order 420. The reduced dynamic orbits of the two probes are determined independent Graz lunar gravity field model to spherical harmonic degree and order 420. The reduced dynamic orbits of the two probes are determined using variational equations following a batch least squares differential adjustment process. These orbits are based on S-band radiometric tracking data collected by the Deep Space Network (DSN) and are used for the independent GRAIL gravity field recovery. To reveal a highly accurate lunar gravity field, collected by the Deep Space Network (DSN) and are used for the independent GRAIL gravity field recovery. To reveal a highly accurate lunar gravity field, an integral equation approach using short orbital arcs is adopted to process the KBR data. A comparison to state-of-the-art lunar gravity models computed at NASA-GSFC, NASA-JPL and AIUB demonstrate the progress of Graz lunar gravity field models derived within the project GRAZIL. at NASA-GSFC, NASA-JPL and AIUB demonstrate the progress of Graz lunar gravity field models derived within the project GRAZIL. RESULTS AND MODEL EVALUATION ORBIT DETERMINATION (POD) GRAVITY FIELD RECOVERY (GFR) RESULTS AND MODEL EVALUATION External solutions exploiting GRAIL data: ORBIT DETERMINATION (POD) Allows for a fully independent solution GRAVITY FIELD RECOVERY (GFR) requires absolute position of GRAIL-A (Ebb) and GRAIL-B (Flow) NASA-GSFC: GRGM660PM [5] POD based on variational equations Batch least squares differential corrector (IWF software) GFR based on short-arc integral equation approach Processing strategy inherited from GRACE (TUG software) 017 NASA-JPL: GL0420A [4] GL0660B [4] Batch least squares differential corrector (IWF software) DSN two-way radiometric tracking data in S-Band Processing strategy inherited from GRACE (TUG software) Inter-satellite ranging data in Ka-Band (KBR) 20 GL0660B [4] AIUB: GRL200A [1] DSN two-way radiometric tracking data in S-Band Inter-satellite ranging data in Ka-Band (KBR) Iterative procedure POD - GFR: Comparison to official orbit product GNI1B (includes KBR data) GRL200B [1] Iterative procedure POD - GFR: a-priori Model SGM150J [2] Comparison to official orbit product GNI1B (includes KBR data) exemplary shown for Ebb: Signal: GRGM660PM (US) POD – S2 Release Model – d/o = 200 Signal: GRGM660PM (US) GL0660B (US) Model – d/o = 200 200 GL0660B (US) GL0420A (US) 300 300 SGM150J (JAP) AIUB-GRL200A (CH) AC.AT 300 POD – L2 350 POD L3-1 420 iterative procedure leads to differences in the range of 10 m: AIUB-GRL200A (CH) AIUB-GRL200B (CH) OEAW.A POD L3-1 420 420 POD L5 AIUB-GRL200B (CH) GER@O 420 POD L5 POD N5 420 GrazLGM200a [3] NSBERG 420 POD N6 GrazLGM420a GrazLGM200a [3] GrazLGM420a .WIRN GrazLGM420a Post-fit residuals of DSN two-way tracking data: GrazLGM420a+ ARALD. Post-fit residuals of DSN two-way tracking data: Free air gravity anomalies near side (left) and far side (right): IA, HA GrazLGM420a GrazLGM420a: Completely independent solution up to d/o 420 GrazLGM420a+: GL0660B as background model for d/o > 420 AUSTRI GrazLGM420a+: GL0660B as background model for d/o > 420 REFERENCES [1] Arnold, D., et al., 2015: Icarus, 261, 182-192. RAZ, A Residual RMS of last iteration is around 1.8mHz during PM phase: [1] Arnold, D., et al., 2015: Icarus, 261, 182-192. [2] Gossens, S., et al., 2011: J. Geod., 85, 487-504. [3] Klinger, B. et al., 2014: Planet. Space Sci., 91, 83-90. AW, GR Residual RMS of last iteration is around 1.8mHz during PM phase: [3] Klinger, B. et al., 2014: Planet. Space Sci., 91, 83-90. [4] Konopliv, A.S. et al., 2014: Geophys. Res. Lett., 41, 1452-1458. [5] Lemoine, F.G. et al., 2014: J. Geophys. Res. (Planets), 118, 1676-1698. WF/ÖA [5] Lemoine, F.G. et al., 2014: J. Geophys. Res. (Planets), 118, 1676-1698. IW We acknowledge the financial support by the Austrian Research We acknowledge the financial support by the Austrian Research Promotion Agency (FFG) for funding the project GRAZIL.
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
WW
W.I
WF.
OEA
W.A
C.A
T FIRST INDEPENDENT LUNAR GRAVITY FIELD SOLUTION IN THE W
WW
.IW
F.O
EAW
.AC.A
T FIRST INDEPENDENT LUNAR GRAVITY FIELD SOLUTION IN THE
FRAMEWORK OF PROJECT GRAZIL
WW
W.I
WF.
OEA
W.A
C.A
T
FRAMEWORK OF PROJECT GRAZIL
WW
W.I
WF.
OEA
W.A
C.A
T
Harald Wirnsberger1, Sandro Krauss1, Beate Klinger2, Torsten Mayer-Gürr2
WW
W.I
WF.
OEA
W.A
C.A
T
1Space Research Institute, Austrian Academy of Sciences; 2Institute of Geodesy, Graz University of Technology
The twin satellite mission Gravity Recovery and Interior Laboratory (GRAIL) aims to recovering the lunar gravity field by means of intersatellite Ka-bandranging (KBR) observations. In order to exploit the potential of KBR data, absolute position information of the two probes is required. Hitherto, the Grazranging (KBR) observations. In order to exploit the potential of KBR data, absolute position information of the two probes is required. Hitherto, the Grazlunar gravity field models (GrazLGM) relies on the official orbit products provided by NASA. In this contribution, we present for the first time a completelyindependent Graz lunar gravity field model to spherical harmonic degree and order 420. The reduced dynamic orbits of the two probes are determinedindependent Graz lunar gravity field model to spherical harmonic degree and order 420. The reduced dynamic orbits of the two probes are determinedusing variational equations following a batch least squares differential adjustment process. These orbits are based on S-band radiometric tracking datacollected by the Deep Space Network (DSN) and are used for the independent GRAIL gravity field recovery. To reveal a highly accurate lunar gravity field,collected by the Deep Space Network (DSN) and are used for the independent GRAIL gravity field recovery. To reveal a highly accurate lunar gravity field,an integral equation approach using short orbital arcs is adopted to process the KBR data. A comparison to state-of-the-art lunar gravity models computedat NASA-GSFC, NASA-JPL and AIUB demonstrate the progress of Graz lunar gravity field models derived within the project GRAZIL.at NASA-GSFC, NASA-JPL and AIUB demonstrate the progress of Graz lunar gravity field models derived within the project GRAZIL.
RESULTS AND MODEL EVALUATIONORBIT DETERMINATION (POD) GRAVITY FIELD RECOVERY (GFR) RESULTS AND MODEL EVALUATION� External solutions exploiting GRAIL data:
ORBIT DETERMINATION (POD) � Allows for a fully independent solution
GRAVITY FIELD RECOVERY (GFR)� requires absolute position of GRAIL-A (Ebb) and GRAIL-B (Flow)
NASA-GSFC: GRGM660PM [5]� POD based on variational equations
� Batch least squares differential corrector (IWF software)
� GFR based on short-arc integral equation approach
� Processing strategy inherited from GRACE (TUG software)
20
17
NASA-JPL: GL0420A [4]GL0660B [4]
� Batch least squares differential corrector (IWF software)
� DSN two-way radiometric tracking data in S-Band
� Processing strategy inherited from GRACE (TUG software)
� Inter-satellite ranging data in Ka-Band (KBR)
20
17
GL0660B [4]
AIUB: GRL200A [1]
� DSN two-way radiometric tracking data in S-Band � Inter-satellite ranging data in Ka-Band (KBR)
Iterative procedure POD - GFR:Comparison to official orbit product GNI1B (includes KBR data)AIUB: GRL200A [1]
GRL200B [1]Iterative procedure POD - GFR:
a-priori Model SGM150J [2]
Comparison to official orbit product GNI1B (includes KBR data)exemplary shown for Ebb:
Signal: GRGM660PM (US)a-priori Model SGM150J [2]
POD – S2 Release
Model – d/o = 200
Signal: GRGM660PM (US)
GL0660B (US)Model – d/o = 200
200
GL0660B (US)
GL0420A (US)200300300
SGM150J (JAP)
AIUB-GRL200A (CH)
@O
EAW
.AC.A
T300POD – L2 350
POD L3-1 420iterative procedure leads to differences in the range of 10 m:
AIUB-GRL200A (CH)
AIUB-GRL200B (CH)
@O
EAW
.AC.A
T
POD L3-1 420
420 POD L5
AIUB-GRL200B (CH)
HARALD
.WIR
NSB
ERG
ER@
OEA
W.A
C.A
T
420 POD L5
POD N5 420GrazLGM200a [3]
HARALD
.WIR
NSB
ERG
ER
420 POD N6
GrazLGM420a
GrazLGM200a [3]
GrazLGM420a
HARALD
.WIR
NSB
ERG
ER
GrazLGM420a
Post-fit residuals of DSN two-way tracking data:
GrazLGM420a
GrazLGM420a+
HARALD
.WIR
NSB
ERG
ER
Post-fit residuals of DSN two-way tracking data:Free air gravity anomalies near side (left) and far side (right):
GRAZ,
AU
STRIA
, H
ARALD
.WIR
NSB
ERG
ER
GrazLGM420a � GrazLGM420a: Completely independent solution up to d/o 420
� GrazLGM420a+: GL0660B as background model for d/o > 420
GRAZ,
AU
STRIA
,
� GrazLGM420a+: GL0660B as background model for d/o > 420
REFERENCES[1] Arnold, D., et al., 2015: Icarus, 261, 182-192. G
RAZ,
AU
STRIA
,
Residual RMS of last iteration is around 1.8mHz during PM phase: [1] Arnold, D., et al., 2015: Icarus, 261, 182-192.[2] Gossens, S., et al., 2011: J. Geod., 85, 487-504.[3] Klinger, B. et al., 2014: Planet. Space Sci., 91, 83-90.
/ÖAW
,G
RAZ,
AU
STRIA
,
Residual RMS of last iteration is around 1.8mHz during PM phase:
[3] Klinger, B. et al., 2014: Planet. Space Sci., 91, 83-90.[4] Konopliv, A.S. et al., 2014: Geophys. Res. Lett., 41, 1452-1458.[5] Lemoine, F.G. et al., 2014: J. Geophys. Res. (Planets), 118, 1676-1698. IW
F/Ö
AW,
[5] Lemoine, F.G. et al., 2014: J. Geophys. Res. (Planets), 118, 1676-1698. IWF
We acknowledge the financial support by the Austrian Research We acknowledge the financial support by the Austrian Research Promotion Agency (FFG) for funding the project GRAZIL.
Related Documents
