Journal of Geodetic Science (Dec 2019)

The topographic bias in gravimetric geoid determination revisited

  • Sjöberg Lars E.

DOI
https://doi.org/10.1515/jogs-2019-0007
Journal volume & issue
Vol. 9, no. 1
pp. 59 – 64

Abstract

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The topographic potential bias at geoid level is the error of the analytically continued geopotential from or above the Earth’s surface to the geoid. We show that the topographic potential can be expressed as the sum of two Bouguer shell components, where the density distribution of one is spherical symmetric and the other is harmonic at any point along the normal to a sphere through the computation point. As a harmonic potential does not affect the bias, the resulting topographic bias is that of the first component, i.e. the spherical symmetric Bouguer shell. This implies that the so-called terrain potential is not likely to contribute significantly to the bias. We present three examples of the geoid bias for different topographic density distributions.

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