Research and measuring stations

Mesähovi Research Station

The Metsähovi research station is subordinated to the Department of Geodesy and Geodynamics. The research station consists of the space geodetic station, gravity laboratory and affiliated research station at Sjökulla. At the research station there is a coordination group representing all the departments, led by the head of the research station. The group deals with subjects concerning the organisation and maintenance of the research station.

More about Metsähovi research station

Nummela Standard Baseline

The Nummela Standard Baseline is a measurement standard for length measurements in geodesy. The baseline was established in year 1933. The length, 864 122.86 mm ±0.07 mm, is measured with the Väisälä comparator, based on white light interferometry, latest in year 2007. The baseline is used for calibration of the most precise electronic distance measurement instruments.

The lengths between observation pillars range from 24 m to 864 m. The baseline was established in 1933 for calibrations of invar wires. They were used to determine the scale of mapping in Finland. Since 1947 the FGI has measured the baseline 15 times using a Väisälä comparator, based on white light interferometry. The length of the entire baseline has varied only 0.6 mm in 60 years. The measurement result in year 2007 was 864 122,86 mm ±0,07 mm. The scale is traceable to the definition of the metre. The long history, favourable environmental conditions and extreme accuracy have made the baseline internationally renowned. Nowadays the most accurate electronic distance measurement instruments are calibrated at the Nummela Standard Baseline. Using them the scale has during the last years been transferred, for example, to Estonia, Lithuania, Austria, Germany, Spain, China and South Korea. The baseline also serves in testing of new absolute distance measurement Instruments.