Struve arcing ring

The United Nations Scientific, Educational and Cultural Organization has recognized Estonia's Struve Surveying Circles and nine other countries as World Cultural Heritage in 2005.

Surveying Struve is a series of triangular surveying stations extending from Hammerfest in Norway to the Black Sea, running through 10 countries with a length of over 2,820km. This series of stations was founded and used by German scientist Friedrich Georg Wihelm von Struve between 1816 and 1855 to establish the exact size and shape of the Earth. At the time of establishment, this series of surveying stations only ran through two countries: Sweden - Norway and the Russian Empire. From then on it was connected to the construction and extension until the end of this survey arc running through all 10 countries.

The route map of the struve arcs of crossings through 10 countries

In 2005, Unesco recognized a series of survey stations including 34 base stations which are memorial stations and milestones marked as world cultural heritage under the following criteria: (ii), (iv), (vi ).

Criteria (ii): Struve arc is the first accurate measurement of a long segment of a meridian. This measurement helps to establish the exact size and shape of the world. This is an important step in the development of earth science.

Criterion (iv): Struve calibrating arc is an outstanding proof for the development of meridian measurement technology - an important and irreplaceable part of measurement technology.

Criterion (vi): The measurement method of the Struve arithmetic circle is linked to Issac Newton's theory of dynamics.

Struve arcs can be interpreted as a long section of a meridian , helping to define, set and correct the shape of the world. Since 500 BC, scholars, scientists have known that Earth is not a plane but no one imagines it to be spherical. By the 3rd century BC, surveying techniques and theory to determine the size and shape of the Earth began to be studied by scholar Eratosthenes. According to Eratosthenes's theory, using dimensions and angles is determined by observing the stars from which to calculate the size of the earth but this does not give a true number, besides the input devices at that time, there were many shortages, so it was impossible to calculate specifically.

Some milestones and memorials of surveying arcs in a number of different countries.

Until the 17th century AD when science and technology were much more advanced, the measurement methods also developed with a new measurement method called Triangulations . According to this method, a short line can be measured more accurately than a long section and connects multiple sections into triangles that form triangles that last up to several hundred kilometers, giving the correct number of segments.

This triangular method was implemented in 1730 to show the true shape of the earth but to make the earth's size more complicated. Some scientists of countries such as France, Peru, Italy, Austria . have also sought to connect the triangles together to find the true size of the earth but all failed.

Doctor Wihelm Stuve.

Until 1815 with the support of Tsar Alexander I , Russian scholars were given good conditions to learn, researched ways to calculate the size of the earth and the scientist Wihelm Struve succeeded with the circle. supply your surveying. A long arc was completed in 1840 and this is the first step for the development of modern surveying frames on today's topographic maps.

The first arc was placed in Estonia because at that time the scientist Wihelm Struve was working and studying here. He decided to set an arc in a line of snowballs passing through the observatory at several locations and from there to extend. His work was then carried out and completed by many different countries' research groups. Struve calibrating arc after completion is 2,820 km long, running through 10 countries including: Estonia, Sweden, Norway, Finland, Russia, Moldova, Ukraine, Latvia, Lithuania, Belarus .