Journal of Geodesy

, Volume 86, Issue 5, pp 319–335 | Cite as

Simulation study of a follow-on gravity mission to GRACE

Original Article

Abstract

The gravity recovery and climate experiment (GRACE) has been providing monthly estimates of the Earth’s time-variable gravity field since its launch in March 2002. The GRACE gravity estimates are used to study temporal mass variations on global and regional scales, which are largely caused by a redistribution of water mass in the Earth system. The accuracy of the GRACE gravity fields are primarily limited by the satellite-to-satellite range-rate measurement noise, accelerometer errors, attitude errors, orbit errors, and temporal aliasing caused by un-modeled high-frequency variations in the gravity signal. Recent work by Ball Aerospace & Technologies Corp., Boulder, CO has resulted in the successful development of an interferometric laser ranging system to specifically address the limitations of the K-band microwave ranging system that provides the satellite-to-satellite measurements for the GRACE mission. Full numerical simulations are performed for several possible configurations of a GRACE Follow-On (GFO) mission to determine if a future satellite gravity recovery mission equipped with a laser ranging system will provide better estimates of time-variable gravity, thus benefiting many areas of Earth systems research. The laser ranging system improves the range-rate measurement precision to ~0.6 nm/s as compared to ~0.2 μm/s for the GRACE K-band microwave ranging instrument. Four different mission scenarios are simulated to investigate the effect of the better instrument at two different altitudes. The first pair of simulated missions is flown at GRACE altitude (~480 km) assuming on-board accelerometers with the same noise characteristics as those currently used for GRACE. The second pair of missions is flown at an altitude of ~250 km which requires a drag-free system to prevent satellite re-entry. In addition to allowing a lower satellite altitude, the drag-free system also reduces the errors associated with the accelerometer. All simulated mission scenarios assume a two satellite co-orbiting pair similar to GRACE in a near-polar, near-circular orbit. A method for local time variable gravity recovery through mass concentration blocks (mascons) is used to form simulated gravity estimates for Greenland and the Amazon region for three GFO configurations and GRACE. Simulation results show that the increased precision of the laser does not improve gravity estimation when flown with on-board accelerometers at the same altitude and spacecraft separation as GRACE, even when time-varying background models are not included. This study also shows that only modest improvement is realized for the best-case scenario (laser, low-altitude, drag-free) as compared to GRACE due to temporal aliasing errors. These errors are caused by high-frequency variations in the hydrology signal and imperfections in the atmospheric, oceanographic, and tidal models which are used to remove unwanted signal. This work concludes that applying the updated technologies alone will not immediately advance the accuracy of the gravity estimates. If the scientific objectives of a GFO mission require more accurate gravity estimates, then future work should focus on improvements in the geophysical models, and ways in which the mission design or data processing could reduce the effects of temporal aliasing.

Keywords

GRACE Time-variable gravity Mass transport Satellite gravimetry 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Bender PL, Nerem RS, Wahr JM (2003) Possible future use of laser gravity gradiometers. Space Sci Rev 108: 385–392CrossRefGoogle Scholar
  2. Bertiger W, Bar-Sever Y, Bettadpur B, Desai S, Dunn C, Haines B, Kru-izinga G, Kuna D, Nandi S, Romans L, Watkins M, Wu S (2002) GRACE millimeters and microns in orbit. In: Proceedings of ION GPS 2002, PortlandGoogle Scholar
  3. Carrère L, Lyard F (2003) Modeling the barotropic response of the global ocean to atmospheric wind and pressure forcing—comparison with observations. Geophys Res Lett 30(6): 1275–1278. doi: 10.1029/2002G016473 CrossRefGoogle Scholar
  4. Dehne M, Cervantes FG, Sheard B, Heinzel G, Danzmann K (2009) Laser interferometer for spaceborne mapping of the Earth’s gravity field. J Phys Conf Ser 154. doi: 10.1008/1742-6596/154/1/012023
  5. Flechtner F (2007) AOD1B product description document for product releases 01 to 04, GRACE 327-750 (GR-GFZ-AOD-0001)Google Scholar
  6. Flury J, Rummel R (2006) Future satellite gravimetry and Earth dynamics. In: Flury J, Rummel R (eds) Earth, Moon, and Planets, vol 94. Nr. 1, Springer, ISBN (Print) 978-0387-29796-5. doi: 10.1007/0-387-33185-9
  7. Han S-C, Jekeli C, Shum CK (2004) Time-variable aliasing effects of ocean tides, atmosphere, and continental water mass on monthly mean GRACE gravity field. J Geophys Res 109: B04403. doi: 10.1029/2003JB002501 CrossRefGoogle Scholar
  8. Kang Z, Tapley B, Bettadpur S, Ries J, Nagel P (2006) Precise orbit determination for grace using accelerometer data. Adv Space Res 38: 2131–2136CrossRefGoogle Scholar
  9. Kim J-R (2000) Simulation study of a low-low satellite-to-satellite tracking mission, Ph.D. thesis, University of Texas, AustinGoogle Scholar
  10. Lefèvre F, Lyard F, LeProvost C, Schrama E (2002) FES99: a global tide finite element solution assimilating tide gauge and altimetric information. J Atmos Ocean Technol 19: 1345–1356CrossRefGoogle Scholar
  11. Luthcke SB, Arendt AA, Rowlands DD, McCarthy JJ, Larsen CF (2008) Recent glacier mass changes in the Gulf of Alaska region from GRACE mascon solutions. J Glaciol 54(188): 767–777CrossRefGoogle Scholar
  12. Luthcke SB, Rowlands DD, Lemoine FG, Klosko SM, Chinn D, McCarthy JJ (2006) Monthly spherical harmonic gravity field solutions determined from GRACE inter-satellite range-rage data alone. Geophys Res Lett 33: L02402. doi: 10.1029/2005GL024846 CrossRefGoogle Scholar
  13. Marchetti P, Blandino JJ, Demetriou MA (2008) Electric propulsion and controller design for drag-free spacecraft operation. J Spacecraft Rockets 45(6): 1303–1315. doi: 10.2514/1.36307 CrossRefGoogle Scholar
  14. Nerem RS, Bender P, Loomis B, Watkins MM, Folkner WM, Stephens M, Craig R, Leitch J, Pierce R (2006) Development of an interferometric laser ranging system for a follow-on gravity mission to GRACE. Eos Trans AGU 87(52), Fall Meet. Suppl. Abstract G11B-02Google Scholar
  15. Pierce R, Leitch J, Stephens M, Bender P, Nerem RS (2008) Intersatellite range monitoring using optical interferometry. Appl Opt 47(27): 5007–5018CrossRefGoogle Scholar
  16. Ray RD (1999) A global ocean tide model from TOPEX/POSEIDON altimetry: GOT99, NASA technical memorandum 209478, Goddard Space Flight CenterGoogle Scholar
  17. Rodell M, Houser PR, Jambor U, Gottschalck J, Mitchell K, Meng C-J, Arsenault K, Cosgrove B, Radakovich J, Bosilovich M, Entin JK, Walker JP, Lohmann D, Toll D (2004) The global land data assimilation system. Bull Am Meteorol Soc 85: 381–394CrossRefGoogle Scholar
  18. Rowlands DD, Luthcke SB, McCarthy JJ, Klosko SM, Chinn DS, Lemoine FG, Boy J-P, Sabaka T (2010) Global mass flux solutions from GRACE; a comparison of parameter estimation strategies: mass concentrations versus Stokes coefficients. J Geophys Res 115: B01403. doi: 10.1029/2009JB006546 CrossRefGoogle Scholar
  19. Rummel R (2003) How to climb the gravity wall. Space Sci Rev 108: 1–14. doi: 10.1023/A:1026206308590 CrossRefGoogle Scholar
  20. Seo KW, Wilson CR, Chen J, Waliser DE (2008) GRACE’s spatial aliasing error. Geophys J Int 172: 41–48. doi: 10.1111/j.1365-246X.2007.03611.x CrossRefGoogle Scholar
  21. Seo KW, Wilson CR (2005) Estimating GRACE aliasing errors. Int Assoc Geod Symp 129: 339–345. doi: 10.1007/b138327 CrossRefGoogle Scholar
  22. Sneeuw N, Flury J, Rummel R (2005) Science requirements on future missions and simulated mission scenarios. Earth Moon Planets 94(1): 113–142. doi: 10.1007/s11038-004-7605-x CrossRefGoogle Scholar
  23. Swenson S, Wahr J (2002) Methods for inferring regional surface-mass anomalies from Gravity Recovery and Climate Experiment (GRACE) measurements of time-variable gravity. J Geophys Res 107(B9): 2193. doi: 10.1029/2001JB000576 CrossRefGoogle Scholar
  24. Tapley BD, Bettadpur S, Watkins M, Reigber C (2004) The gravity recovery and climate experiment: mission overview and early results. Geophys Res Lett 31: L24806. doi: 10.1029/2004GL021220 CrossRefGoogle Scholar
  25. Tapley B, Ries J, Bettadpur S, Chambers D, Cheng M, Condi F, Gunter B, Kang Z, Nagel P, Pastor R, Pekker T, Poole S, Wang F (2005) GGM02—An improved earth gravity field model from GRACE. J Geod. doi: 10.1007/s00190-005-0480-z
  26. Thompson PF, Bettadpur SV, Tapley BD (2004) Impact of short period, non-tidal, temporal mass variability on GRACE gravity estimates. Geophys Res Lett 31: L06619. doi: 10.1029/2003GL019285 CrossRefGoogle Scholar
  27. van Dam T, Visser P, Sneeuw N, Losch M, Gruber T, Bamber J, Bierkens M, King M, Smit M (2008) Monitoring and modeling individual sources of mass distribution and transport in the Earth system by means of satellites. Final Report, ESA Contract No. 20403Google Scholar
  28. Wahr J, Swenson S, Zlotnicki V, Velicogna I (2004) Time-variable gravity from GRACE: first results. Geophys Res Lett 31: L11501. doi: 10.1029/2004GL019779 CrossRefGoogle Scholar
  29. Wiese D N, Folkner W M, Nerem R S (2008) Alternative mission architecture for a gravity recovery satellite mission. J Geod. doi: 10.1007/s00190-008-0274-1
  30. Wunsch C, Stammer D (1997) Atmospherical loading and the oceanic ’inverted barometer’ effect. Rev Geophys 35(1): 79–107CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  • Bryant D. Loomis
    • 1
    • 2
  • R. S. Nerem
    • 3
  • S. B. Luthcke
    • 4
  1. 1.University of Colorado at BoulderBoulderUSA
  2. 2.SGT Inc.GreenbeltUSA
  3. 3.Colorado Center for Astrodynamics ResearchUniversity of Colorado at BoulderBoulderUSA
  4. 4.Planetary Geodynamics Laboratory, NASA Goddard Space Flight Center, Code 698GreenbeltUSA

Personalised recommendations