Geodetic activities in Latin America and The Caribbean: always IN
Readers may recall that we have published an article” Geodesy: Out with the Old, In with the New” by Prof Chris Rizos in November We present here some observations of SIRGAS on that article and clarification by Prof Rizos
C Bruninit
SIRGAS President
L Sánchez
SIRGAS Vice-President
Geodesy has taken several important steps forward since the early days in which it was defined by Helmert as the science devoted to measuring and mapping the Earth’s surface. Today, the challenge of modern Geodesy is to incorporate within Helmert’s definition the determination of many more parameters of the “Earth System”. As in other fields, the continuous and relentless transition from the “old” Geodesy to the “new” Geodesy generates controversial discussions within the geodetic community. One point of view regarding this process was recently proposed by Prof. Chris Rizos in his article “Geodesy: Out with the Old, In with the New”, published in Coordinates (vol. VII, No. 11, November ). We have read this article with interest and appreciate the opportunity offered to us by the Coordinates’ Editor to debate the point of view presented there regarding the evolution of Geodesy in different parts of the world. We hope the arguments presented in the following paragraphs provide valuable information regarding the current situation of Geodesy in the Latin America and Caribbean regions.
From Chris’ article we particularly quote the following paragraph: “It must be pointed out however, that the representation of countries from South America, Asia and Africa, as hosts of GNSS tracking stations, as homes to product analysis centres, and on its governance body is disappointing. Nevertheless, some progress is being made with the Asia-Pacific Reference Frame Project (APREF – http://www. ), which aims to encourage cross-border cooperation in GNSS geodesy; and t
History of geodesy
The history of geodesy (/dʒiːˈɒdɪsi/) began during antiquity and ultimately blossomed during the Age of Enlightenment.
Many early conceptions of the Earth held it to be flat, with the heavens being a physical dome spanning over it. Early arguments for a spherical Earth pointed to various more subtle empirical observations, including how lunar eclipses were seen as circular shadows, as well as the fact that Polaris is seen lower in the sky as one travels southward.
Hellenic world
Initial developments
Though the earliest written mention of a spherical Earth comes from ancient Greek sources, there is no account of how the sphericity of Earth was discovered, or if it was initially simply a guess. A plausible explanation given by the historian Otto E. Neugebauer is that it was "the experience of travellers that suggested such an explanation for the variation in the observable altitude of the pole and the change in the area of circumpolar stars, a change that was quite drastic between Greek settlements" around the eastern Mediterranean Sea, particularly those between the Nile Delta and Crimea.
Another possible explanation can be traced back to earlier Phoenician sailors. The first circumnavigation of Africa is described as being undertaken by Phoenician explorers employed by Egyptian pharaoh Necho IIc.&#;–&#;BC. In The Histories, written –&#;BC, Herodotus cast doubt on a report of the Sun observed shining from the north. He stated that the phenomenon was observed by Phoenician explorers during their circumnavigation of Africa (The Histories, ) who claimed to have had the Sun on their right when circumnavigating in a clockwise direction. To modern historians, these details confirm the truth of the Phoenicians' report. The historian Dmitri Panchenko hypothesizes that it was the Phoenician circumnavigation of Africa that inspired the theory of a spherical Earth, the ear
Past Officers (Presidents and General Secretaries) of the IAG
Direct link to the entities
(Mittel-) Europaeische Gradmessung: Central Bureau / Perm. Commission
Internationale Erdmessung / Association Géodésique Internationale
International Union of Geodesy and Geophysics - Section Geodesy
IUGG - International Association of Geodesy: Presidents
IUGG - International Association of Geodesy: General Secretaries
(Mittel-)Europäische Gradmessung
Johann Jakob Baeyer,Director ().
Director ()
Johann Jakob Baeyer was a student and disciple of Bessel and an officer of the Prussian General Staff. He was admitted to the geodetic institution in and served as a director from until he retired in He had recognized the importance of large-scale astrogeodetic systems for the determination of the figure of the Earth. After his retirement he concentrated on this problem, influenced also by his appointment as Prussian representative to the longitude arc measurements at 52° latitude, which was proposed by Wilhelm Struve, then director of the Dorpat astronomical observatory. In April , Baeyer presented a ‘Proposal for a Central European Arc Measurement’ to the Prussian Minister of War, and justified this project by a comprehensive memorial on the size and figure of the Earth, which he dedicated to the memory of Alexander von Humboldt. At the end of , Baeyer was able to identify 16 states or countries that had entered the project: Austria, Belgium, Denmark, France (allowed the use of data necessary for the project), seven German states (Baden, Bavaria, Hannover, Mecklenburg, Prussia, Kingdom of Saxony, Saxe-Gotha), Italy, The Netherlands, Poland (through Russia), Sweden and Norway (in personal union), and Switzerland. This was a great success: an international scientific (governmental) organization had been established within a remarkably short time.
Peter Andreas HANSEN (),
President ()
The son of a goldsmith, Hansen learned the trade of a watchmaker at Flensburg, and exe