Geoid and Leveling

As we know, the behavior of the potential W p) of the gravitational field can be illustrated with the help of the equipotential or level surfaces 

As was pointed out earlier, the determination of the elevation of points of the physical surface of the earth with respect to the geoid is the only the first step in studying the shape of the earth. The next step is the calculation of the distance between corresponding points of the ellipsoid of rotation and the geoid, and this subject will be described in the following section. 

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