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Description:
This geoid is an update
on an earlier model (AGP2007) of the
geoid for Africa, and incorporates new
contributions from the KMS02 marine
gravity dataset, the SRTM30DEM and
long wavelength harmonic coefficients
from the Eigen-GRACE GL04C model. A
uniform 5' grid of gravity anomalies
derived from terrestrial gravity data
has been combined with the marine
data, and the combined dataset has
been used with the geopotential model
in a remove restore process. Two
dimensional convolution has been used
to computer residual height anomalies
from residual gravity anomalies,
including the contribution of the
Molodensky G1 term. The geopotential
model contribution has been restored
and the height anomalies converted to
geoidal heights. The final result is a
5' grid of geoidal heights covering
the land mass of Africa.
There are significant
gaps in the available terrestrial
gravity data. These gaps mean that the
accuracy of the final geoid model will
be variable and generally less than
desirable. Nevertheless good agreement
is achieved with GPS/levelling results
in western South Africa and northern
Algeria.
References:
C.L. Merry (2007). An
updated geoid model for Africa.
Presented at Symposium G2, XXIV General Assembly of the IUGG, Perugia, Italy, July 2007.
Web of Science ID:
DRCI:DATA2014041004285928
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