Orthometric height

As we know, the quantity Ah is called the elevation or an orthometric height of the point b with respect to point b. In particular, if both points are located at the same level surface, this elevation is zero. If we take a different path, for instance, aa b, Equation (2.255) gives a height of the point a with respect to a, which can differ from the first one. 

Add of surface forces height, mechanical ellipticity orthometric height elevation... 

With the same degree of precision this formula is valid for the variations of normal and normal-orthometric heights, too. The amplitudes of the main diurnal and semi-diurnal constituents are demonstrated in table 5. The maximum peak—to-peak variation of physicjdly defined heights due to tidal actions is about 53 cm. 

Equivalently, the effects on orthometric height differences can be evaluated... 

During tunnel boring, height information inside the tunnels can only be obtained by geometric levelling. This technique results in orthometric height differences... 

In this method the deflections of the vertical are derived from measured ellipsoidal and orthometric height differences 6h and 6H by... 

In this method the orthometric height differences 6H are not measured directly but derived from simultaneously observed reciprocal zenith angles and... 

Assuming that the refraction has a symmetrical effect on the path of light and the geoid is curved spherically, orthometric height differences 6H can then be obtained from and by... 

This is the equation of a plane, describing the transition from ellipsoidal (GPS) height differences to orthometric height differences Sh — (SH). In figure 3-3 this plane is plotted as... 

GPS combined with geometric levelling yielded the best possible results. Since levelling had to be performed in the portal networks anyway, and GPS measurements were also employed for the purpose of horizontal control the required orthometric height difference between Sjaelland and Sprog0 was gained almost by the by. 

Orthometric height differences from ellipsoidal heights... 

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