Earth tide observatories, equipped with high frequency tiltmeters ASNS, have different functions.
The main observatory in Příbram (PRIB) has favourable position in abandoned deep mine shaft in the depth of 90 meters. Various types of tiltmeters are tested for mutual correlation and estimation of observed trends. The data are occasionally compared with seismologic and gravimetry records.
The Skalná Observatory (SKAL) is located in the West Bohemian seismically active region. It provides tilt data for correlation with earthquakes and changes of the level of subsurface water. Observatory is located in an old castle cellar. In spite of strong thermo-dynamic noise and influence of precipitations we were able to detect signals related to earthquakes.
The Jezeří Observatory is situated in a horizontal gallery on the edge of the large open-pit brown coal mine. The mining disrupted stability of the slopes and observations are aimed at monitoring the massive tilt. The observations are supported by the mining company. We have registered significant signals before and during the landslips. The data are also important for the castle situated directly above the gallery.