International Service for the Geoid


Search in ISG Website



Services - Geoid Repository

Regional Models

Iberia and Macaronesia (ICAGM07)

  Authors: J. Catalao, M.J. Sevilla     Created: 2007    Resp: J. Catalao  
      Status: PUBLIC    
The ICAGM07 model is a gravimetric geoid for the North-East Atlantic Ocean, Iberia, and the Macaronesian Islands (Azores, Madeira and Canary archipelagos). The gravity database includes observed terrestrial and shipborne gravity anomalies and satellite-altimetry derived gravity anomalies from KMS02 model. The geoid model has a grid spacing of 1.5' x 1.5', it is referred to the GRS80 ellipsoid and it has been compted using the remove-restore technique. In particular, long wavelengths of the geoid are provided by the GRACE-derived Earth geopotential EIGEN05C model. The residual topographic correction has been computed using the 100 m resolution digital terrain model derived from SRTM mission data and cartographic charts on land and the 500 m resolution Gebco grid on sea. Finally the residual geoid heights have been computed using spherical FFT and a modified Stokes kernel. Comparisons over sea with an oceanographic geoid determined from CLS01 MSSH and Rio05 MDT yield a relative accuracy of 8 cm, with larger differences close to the shoreline. Over land, comparisons with 1646 GPS/levelling marks indicate an overall precision of 8-10 cm and relative vertical datum offsets of up to 2 m.

J. Catalao, M.J. Sevilla, H. Koll (2007). The ICAGM07 Geoid Model for the North-East Atlantic (Iberia - Canary - Azores). Poster presented at the IUGG2007 General Assembly, Perugia, Italy.
J. Catalao, M.J. Sevilla (2009). Mapping the geoid for Iberia and the Macaronesian Islands using multi-sensor gravity data and the GRACE geopotential model. Journal of Geodynamics, 48(1), pp. 6-15.

Iberia and Macaronesia