The Gravimetric Station Pecný at the Pecný Geodetic Observatory VÚGTK in Ondřejov provides continuous monitoring of changes in gravity acceleration by a combination of measurements from relative and absolute gravimeters. Gravity acceleration measurements are performed at the station using the following instruments:
- Relative superconducting gravimeter OSG-050 manufactured by GWR Instruments, Inc. in USA. Since 2007, the OSG-050 gravimeter has been continuously measuring changes in gravitational acceleration with a recording interval of 1 second. The data is available (after registration) in the IGETS database (International Geodynamic and Earth Tide Service), which is accessible on an FTP server. Quality control of recent data from the OSG-050 gravimeter is available on the SG Noise web page.
- Absolute gravimeter FG5 SN 215 manufactured by Micro-g Solution, Inc. in the USA, it has been in operation at Pecný since 2001. The data are available in the AGrav database (Absolute Gravity Database - database of absolute measurements of gravity acceleration).
- Absolute gravimeter FG5X SN 251 manufactured by Micro-g LaCoste, Inc. in the USA, it has been in operation at the Pecný station since 2014. The data are available in the AGrav database (Absolute Gravity Database - database of absolute measurements of gravity acceleration).
Measurements from a rain gauge, soil moisture sensors and groundwater level are continuously recorded to model local hydrological effects on gravity acceleration at the Pecný station. Measurements are available on request. Data obtained by a combination of measurements from a relative superconducting gravimeter and absolute gravimeters allow the study of changes in gravity acceleration on a wide range of frequencies affecting many geophysical phenomena (natural oscillations of the Earth, earth tides, changes in mass distribution in the atmosphere and hydrosphere, pole motion, crustal motion).