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Regional Models

Portugal (GEODPT08)

  Author: J. Catalao     Created: 2008    Resp: J. Catalao  
      Status: PUBLIC    
The GeodPT08 geoid model has been computed by adjusting the ICAGM07 model to the Portuguese national geodetic network (using 1096 geodetic vertices) and to a levelling network (using 135 levelling marks, homogeneously distributed all over the country). In Portugal mainland the ICAGM07 model has a bias of 84 cm relative to the national altimetric reference system (Cascais Datum). The residuals between the ICAGM07 gravimetric geoid model and the geometric geoid model (ellipsoidal heights minus orthometric heights) were interpolated into a grid using a least squares collocation approach with a Markov-Gauss covariance function depending on the spherical distance only. The resulting grid surface was added to ICAGM07 to derive the GeodPT08 geoid model. The reference ellipsoid is the GRS80 and the coordinate reference system is the ETRS89/PT-TM06 (cartographic). The estimated accuracy is 4 cm.

J. Catalao (2008). Um modelo de geoide para Portugal continental. Universidade de Lisboa, Portugal.