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Regional Models

Caribbean (CARIB97)

  Authors: D.A. Smith, H.J. Small     Created: 1997    Resp: D.A. Smith  
      Status: PUBLIC    

CARIB97 is a geoid model covering the Caribbean Sea, computed by the National Geodetic Survey (NGS). It is referred to the GRS80 normal ellipsoid, centered at the ITRF94 (1996.0) origin. It has a 2'x2' spatial resolution in latitude and longitude. It is based on over seven hundred thousand terrestrial and marine gravity values. The geoid determination is based on Fast Fourier Transform (FFT) technique in the framework of a remove-restore procedure, where long wavelengths come from the EGM96 geopotential model. The permanent tide system of CARIB97 is non-tidal. Comparison of geoid heights to 31 GPS/tidal (ITRF94/local) benchmarks shows a mean offset of -51 cm, with an rms of 62 cm. In addition to the offsets, localized systematic errors are evident on some islands. These systematic errors may appear as tilts, over very short ranges, island by island. Larger systematic errors are expected near Cuba and Venezuela due to a lack of gravity cover.

D.A. Smith, H.J. Small (1999). The CARIB97 high-resolution geoid height model for the Caribbean Sea. Journal of Geodesy, 73(1), pp. 1-9.