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Work for nomination

The Latvian work for nomination of the Struve Geodetic Arc on the UNESCO World Heritage List has mainly been carried out by specialists from Latvian Geospatial Information Agency and lecturers and students from Riga Technical University Civil engineering faculty Department of Geomatics.

Current work

In 2015 specialists from Latvian Geospatial Information Agency carried out inspection of all 16 Struves geodetic arc points in Latvia. After inspection summarized report with current information about each Struve geodetic arc point was prepared. Also a point’s passport was prepared for each point of the Struves geodetic arc and a photo fixation was carried out.

In May 11, 2018 the first meeting of Struve Geodetic Arc Preservation and Development Council was held. The Council consists of 17 members: 3 representatives from Latvian Geospatial Information Agency (LGIA), 1 representative from UNESCO Latvia, 2 representatives from the National Heritage Protection Inspection and one representative from each municipalities with Struve Geodetic arc points (11). In the meeting the Council's Statute is planned to approve. Also Struve Geodetic Arc Management plan developed by LGIA will be discussed.

Results

Latvia is the only country in which both Friedrich Georg Wilhelm von Struve, as well Karl Tenner made measurements and built the station points. Wilhelm von Struve surveyed Northern part of Latvia till the point Jacobstatd, while Karl Tenner surveyed points in Southern part of Latvia – from Bristen to Pilkaln. There are 16 points entirely, from whom 11 are organized by Struve and 5 are organized by Tenner.

Two station points of Struve Geodetic Arc chain in Latvia - Sestu-Kalns (Ziestu) and Jacobstatd are designated as UNESCO World Heritage Sites.

The Sestu-Kalns geodetic point of Struve Meridian is located on the Ziestu hill (216,5 above sea level) in Sausneja Municipality, Madona Distric, close to the road Ērgļi – Koknese.
During establishing of the chain in 1824, the Sestu-Kalns point was properly marked and remain untouched until 1904, when Russian Military surveyors reconstructed it and included in new 1st Class triangulation chain and tied it up to prior line Sestukalns – Gaisakalns of the Struve Chain. Reconstructed point was marked with large granit stone carying inscribed year of reconstruction and the cross-typical surveying symbol.

The geodetic station point Jacobstatd, which also served as the place of astronomical observation, is located in Jekabpils town, Struve park. Total area of the park is 1,2 ha and it is tight by Struve street, both named to honour work of outstanding geodesist and astronomer Friedrich Georg Wilhelm von Struve.
The measuring of Jacobstatd point concluded the establishing the part of Struve chain- from Tarty to Jekabpils, these works were completed between 1822-1827. This point served as tieback to triangulation chains in Kurzeme and Lithuania, established by Karl Tenner. Through the establishing of the Jacobstatd point the Struve’s intention to include the survey triangulations of Vidzeme and Estonia in united Meridian was materialized. Jacobstatd point was measured and established in May—June 1826.

In August 17-19 2011 specialists of Latvian Geospatial Information Agency and Riga Technical University organized an expedition to geodetic station point Bristen in Jaunjelgava District. The task of the expedition was to detect precise location of geodetic station point and to find the foundation of the Observatory. During 3 days of investigation work the Bristen geodetic station point and part of the observatory’s foundation were found. In fact only in August 31st the exact station point was completely revealed – it was located under a brick layer foud in 19th August and considered as the real geodetic point. The granit stone covered by bricks is carying inscribed year of foundation 1828 and the sign of cross.

In September 14, 2015 specialists of Latvian Geospatial Information Agency organized an expedition to Struve geodetic arc point Daborskalns in Sala District. The task of the expedition was to lift off 1st order triangulation point Daborskalns and to uncover lower benchmark. Under triangulation point there was a large stone plate with marked center approximately 5 cm in diameter.

Pictures

Sestukalns_01.jpg
Sestukalns_02.jpg
Struve Geodetic Arc point Sestukalns UNESCO Information plate near Struve Geodetic Arc point Sestukalns
Jacobstadt_01.jpg
Jacobstadt_02.jpg
Struve Geodetic Arc point Jacobstadt UNESCO Information plate near Struve Geodetic Arc point Jacobstadt
Bristen_03.jpg Bristen_05.jpg
Struve Geodetic Arc point Bristen Model of field observatory near Struve Geodetic Arc point Bristen
Daborskalns_01.jpg
Daborskalns_03.jpg
Struve Geodetic Arc point Daborskalns Field work in Struve Geodetic Arc point Daborskalns
Oppekaln_01.jpg
Kreutzburg_01.jpg
Struve Geodetic Arc point Oppekaln Struve Geodetic Arc point Kreutzburg
Ramkau_01.jpg
Nessaulekalns_01.jpg
The approximate location of Struve Geodetic Arc point Ramkau The approximate location of Struve Geodetic Arc point Nessaulekalns

External Links

Struve_UNESCO_logo.jpg UNESCO Latvian National Commission
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