Das Problem der Bestimmung wahrer Meereshöhen und seine schweizerische Lösung

Summary

The gravity values determined in Switzerland by the Swiss geodetic Commission enable us to compute the closing errors in the polygones of the levelling net of the survey. The observed errors do not agree with the computed errors; the differences between the one and the other must be eliminated by a computation of compensation. There results from this computation also a mean error for 1 km; it amounts to ±1,40 mm, so that the mean error of a levelling altitude difference measured over a length of 400 km is equal to ±1,40 √400=±28 mm.

The intrinsic altitude of a point, i. e. the length of the plumbline between the point and the sea level, can only be indicated if the mean gravity value along the plumbline is known. This value can be derived by computation from the surface gravity value of the point. The differences between the levelling altitude and the intrinsic altitude amount to 1 dm in flat regions and reach 3–4 dm in the Alps.