Swiss Geodetic Commission

The Swiss Geodetic Commission is a commission of the Swiss Academy of Sciences, founded in 1861 within the framework of the Central European Arc Measurement, which later became the International Geodetic Association, and then the International Association of Geodesy. It initiates and coordinates geodetic research in Switzerland. It plays an advisory role in the development of Swiss geodetic policies. It contributes to disseminating geodetic knowledge to the general public. It supports the expansion of Swiss geodetic infrastructure, including the introduction of innovative methodologies and technologies. It maintains links with international institutions such as the International Association of Geodesy and the International Union of Geodesy and Geophysics.

Early history In the 19th century in particular, learned societies contributed to the emergence of national consciousness and the emancipation of the bourgeoisie. Their members, who often held influential positions, formed a link between citizens and the administration. The societies carried out public tasks and brought together people of different faiths and backgrounds. They offered scholars the opportunity to freely exchange their ideas outside of academia. During the period of Geneva's annexation to France (1798-1813), the Société des Naturalistes took the name of Société de Physique et d'Histoire Naturelle (SPHN). Respectively since 1801 and 1805, Alessandro Volta and Alexander von Humboldt were honorary members of the SPHN. Henri-Albert Gosse, its founder in 1791, was also behind the creation of the Swiss Academy of Natural Sciences, the first of its kind in Europe, in 1815. In the same year, Switzerland expanded from 19 to 22 cantons with the accession of the cantons of Geneva, Neuchâtel and Valais. Guillaume-Henri Dufour, cantonal engineer in Geneva since 1817 and commissioned by the Federal Diet to superintend land surveying of Switzerland, founded in 1838 in Carouge (canton of Geneva) a topographic office (the future Federal Office of topography), which published under his direction, from 1845 to 1864, the first official map of Switzerland, on the basis of new cantonal measurements. The map of the canton of Geneva, which can be considered Dufour's masterpiece, had been published in 1842. After the Sonderbund War, the country pacified by Guillaume-Henri Dufour adopted a new Swiss Federal Constitution, inspired by the Constitution of the United States, founding the federal state in 1848. Swiss neutrality, imposed on the country at the Congress of Vienna and formally established by the Second Treaty of Paris on 20 November 1815, thanks to the diplomatic role of Ioannis Kapodistrias, forced Switzerland to organize an army capable of repelling any potential invasion attempt, in order to serve as a buffer zone between Austrian Empire and France. Cartography was then the domain of the military. The measurements of Struve Geodetic Arc spanned a period of forty years (1816-1855) and initiated an international scientific collaboration between the Russian Empire and the United Kingdoms of Sweden and Norway, involving eminent astronomers such as Friedrich Georg Wilhelm von Struve, Friedrich Wilhelm Bessel, Carl Friedrich Gauss, and George Biddell Airy. The Swiss Geodetic Commission was created during the publication of the Dufour map, and its initial work contributed to the design of the Topographic Atlas of Switzerland. In 1861, Johan Jacob Baeyer proposed the creation of the Central European Arc Measurement, whose objective was to redetermine anomalies in the shape of the Earth using precise arc measurements combined with gravimetry. The aim was to figure out the geoid using gravimetric and leveling measurements to derive an accurate understanding of the Earth ellipsoid while taking vertical deflections into account. On July 7, 1861, the Prussian delegation in Bern submitted Baeyer's project to the Federal Council. The Federal Department of the Interior submitted it to Guillaume Henri Dufour, head of the Swiss Federal Office of Topography. At the 1861 session of the Swiss Society of Natural Sciences in Lausanne, the project discussed by the physics section of the Society was strongly supported by Élie Ritter and Adolphe Hirsch. On their proposal, the Society decided to give a favorable opinion on Switzerland's accession to the Central European Arc Measurement and to establish the Swiss Geodetic Commission. Its founding members were Rudolf Wolf, president (canton of Zurich), Guillaume Henri Dufour, honorary president and Élie Ritter, soon replaced by Émile Plantamour (canton of Geneva), Adolphe Hirsch (canton of Neuchâtel) and Hans Heinrich Denzler (canton of Bern). Baeyer's goal was a new determination of anomalies in the shape of the Earth using precise triangulations, combined with gravity measurements. This involved determining the geoid by means of gravimetric and leveling measurements, in order to deduce the exact knowledge of the Earth spheroid while taking into account local deflections of the plumb line due to gravity anomalies affecting gravity of Earth. To resolve this problem, it was necessary to carefully study considerable areas of land in all directions. Baeyer developed a plan to coordinate geodetic surveys in the space between the parallels of Palermo and Christiana (Oslo) and the meridians of Bonn and Trunz (German name for Milejewo in Poland). This territory was covered by a triangle network and included more than thirty observatories or stations whose position was determined astronomically. Bayer proposed to remeasure ten arcs of meridians and a larger number of arcs of parallels, to compare the curvature of the meridian arcs on the two slopes of the Alps, in order to determine the influence of this mountain range on vertical deflection. Baeyer also planned to determine the curvature of the seas, the Mediterranean Sea and Adriatic Sea in the south, the North Sea and the Baltic Sea in the north. In his mind, the cooperation of all the States of Central Europe could open the field to scientific research of the highest interest, research that each State, taken in isolation, was not able to undertake.

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