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Preliminary Results of Spatial Modelling of GPS/Levelling Heights: A Local Quasi-Geoid/Geoid for the Lisbon Area

  • A. P. FalcãoEmail author
  • J. Matos
  • A. Gonçalves
  • J. Casaca
  • J. Sousa
Conference paper
  • 2k Downloads
Part of the International Association of Geodesy Symposia book series (IAG SYMPOSIA, volume 135)

Abstract

Taking GPS-measured ellipsoidal heights with in situ measured gravity values, levelling-measured heights, and knowing the difference between normal gravity potential and geoidal potential, the calculation of normal heights is possible. The difference between normal and ellipsoidal heights allows the computation of gravity anomalies and geoid undulation, and thus the calculation of quasi-geoid and geoid surfaces, to serve practical applications such as large scale map production and engineering applications.

In this work an evaluation of the spatial interpolation techniques used in the quasi-geoid/ geoid local calculation methods is presented. Deterministic interpolators (Inverse Power of Distance – IPD and Radial Basis Functions– RBF), and probabilistic interpolators (Ordinary Kriging – OrdK and Kriging with External Drift – KED) were tested. The sample used in this study is from a 34 km × 28 km area including Lisbon, which includes 25 levelling heights and gravity values measured by the Instituto Geográfico Português, and the related ellipsoidal heights, measured with a LEICA AX1200 double-frequency GPS receiver.

Keywords

Quasi-geoid Normal heights Interpolation techniques 

Notes

Acknowledgments

Authors would like to thank Instituto Geográfico Português for data availability.

References

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Copyright information

© Springer-Verlag Berlin Heidelberg 2010

Authors and Affiliations

  • A. P. Falcão
    • 1
    Email author
  • J. Matos
    • 1
  • A. Gonçalves
    • 1
  • J. Casaca
    • 2
  • J. Sousa
    • 3
  1. 1.Departamento de Engenharia Civil e Arquitectura (DECivil)Instituto Superior Técnico, Universidade Técnica de LisboaLisboaPortugal
  2. 2.Laboratório Nacional de Engenharia CivilLisboaPortugal
  3. 3.Departamento de Engenharia de Minas e Georrecursos (DEMG)Instituto Superior Técnico, Universidade Técnica de LisboaLisboaPortugal

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