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Initial results from retracking and reprocessing the ERS-1 geodetic mission altimetry for gravity field purposes

  • Ole B. Andersen
  • P. Knudsen
  • P. A. M. Berry
  • E. L. Mathers
  • R. Trimmer
  • S. Kenyon
Conference paper
Part of the International Association of Geodesy Symposia book series (IAG SYMPOSIA, volume 129)

Abstract

All present global marine gravity fields are based on the lHz ERS-1 Geodetic Mission (GM) altimeter data combined with other altimetric datasets. Close to the coast (<25 km) this investigation shows that the altimetric gravity field determination degrades due to a combination of several factors, where the main reason is the degradation of the quality of the altimeter data. By starting out from the original waveform data and retracking the entire ERS-1 GM mission using a highly advanced expert based system of multiple retrackers, the return time from both open ocean and coastal sea surface as well as from all ice-covered regions within the coverage of the ERS-1 can be derived with higher accuracy than presently available.

Initial results of the combined effort to improve the ERS-1 GM altimetric dataset through retracking and regression to 2Hz (3km) are presented, and its effort on gravity field modeling close to the coast and in Polar Regions is discussed. Close to the coast and in particular in Polar Regions the use of multiple retrackers leads to considerably more and better data than in the normal 1 Hz data delivered by the European Space Agency (ESA).

Extensive comparison with marine gravity field data by the National Geospatial-Intelligence Agency is also presented to document the improvement on gravity field determination

Keywords

Satellite altimetry retracking gravity field determination coastal polar regions 

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References

  1. Andersen, O. B., and P. Knudsen, Global Marine Gravity Field from the ERS-1 and GEOSAT Geodetic Mission Altimetry, J. Geophys. Res., 103, 8129–8137, 1998.CrossRefGoogle Scholar
  2. Andersen, O. B., and Knudsen, P. The Role of Satellite Altimetry in Gravity Field Modelling in Coastal Areas, Physics and Chemistry of the Earth (A), Vol. 25, No. 1, pp. 17–24., 2000CrossRefGoogle Scholar
  3. Andersen, O. B., P. Knudsen, S. Kenyon and R. Trimmer, Recent improvement in the KMS global marine gravity field, Boll Geofis. teor. ed Applic. Vol, 40,3–4, pp 369–377, 1999.Google Scholar
  4. Andersen O. B. and P. Knudsen, Global Marine Gravity Field from the ERS-1 and GEOSAT Geodetic Mission Altimetry, J. Geophys. Res., 103(C4), 8129–8137, 1998.CrossRefGoogle Scholar
  5. Andersen, O. B., P. Knudsen and R. Trimmer, Improved high resolution gravity field mapping (the KMS02 Global Marine gravity field). In press, IAG symposium, 126, Sapporo, 2004Google Scholar
  6. Berry, P.A.M., H. Bracke, and A. Jasper, 1997. Retracking ERS-1 altimeter waveforms over land for topographic height determination: an expert systems approach, ESA Pub. SP414 Vol. 1, 403–408.Google Scholar
  7. Berry, P.A.M., J.D. Garlick, and E.L. Mathers, 2004. Global scale monitoring of land surface water using multi-mission satellite radar altimetry. EGU 1st General Assembly, Nice.Google Scholar
  8. Challenor, P.G., and M.A. Srokosz, 1989. The extraction of geophysical parameters from radar altimeter return from a nonlinear ocean surface, in Brooks, S.R. (ed.) Mathematics in Remote Sensing, Institute of Mathematics and its Applications, pp 257–268.Google Scholar
  9. Cleveland, W.S. (1979) “Robust Locally Weighted Regression and Smoothing Scatterplots,” Journal of the American Statistical Association, Vol. 74, pp. 829–836.CrossRefGoogle Scholar
  10. Cleveland, W.S. and Devlin, S.J. (1988) “Locally Weighted Regression: An Approach to Regression Analysis by Local Fitting,” Journal of the American Statistical Association, Vol. 83, pp. 596–610.CrossRefGoogle Scholar
  11. Fairhead, J. D., C. M. Green, K. M. U. Fletcher, Global mapping deep water hydrocarbon plays of the continental margins, ASEG 17th Geophysical conference and exhibition, Sydney, extended abstract, 2004Google Scholar
  12. Hwang, G. et. al., Satellite radar waveform retracking for improved coastal marine gravity anomaly accuracy in the Taiwan Strait., proceedings of the International Workshop on Satellite Altimetry for Geodesy, Geophysics and Oceanography: Summer Lecture Series and IAG symporium 126, 2003.Google Scholar
  13. Laxon and McAdoo, 1998, Satellites Provide New Insights into Polar Geophysics, EOS, Transactions AGU, 79(6), 69–72.Google Scholar
  14. Sandwell, D. T., and Smith, W.H.F. Marine Gravity Anomaly from Geosat and ERS-1 Satellite Altimetry, Journal of Geophysical Research, Vol. 102, pp. 10039–10054, 1997.CrossRefGoogle Scholar
  15. Wang, Y. M. GSFC00 mean sea surface, gravity anomaly, and vertical gravity gradient from satellite altimeter data., J. Geophys res., 106,C12, 31167–31174, 2001CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2005

Authors and Affiliations

  • Ole B. Andersen
    • 1
  • P. Knudsen
    • 1
  • P. A. M. Berry
    • 2
  • E. L. Mathers
    • 2
  • R. Trimmer
    • 3
  • S. Kenyon
    • 3
  1. 1.Danish Space CenterCopenhagenDenmark
  2. 2.EAPRS LaboratoryDe Montfort UniversityLeicesterUK
  3. 3.National Geospatial-Intelligence Agency, GIMGSt LouisUSA

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