The database (ORACLE) contains magnetic anomalies delta ?T that has been measured by airborne magnetometry survey at scale 1:25,000 since 1960 (about 85 % of the whole territory); the rest is covered by measurement at scale 1:200,000 (1958-1960). The period 1960-1971 is represented by analogue recording (flux-gate magnetometer) with accuracy ca 10 nT. The next measuremets have been carried out using digital registration (proton or cesium magnetometer) with accuracy ca 2 nT. The results of ground magnetometry is added to the airborne magnetometry data in region of Eastern Moravia, Krkonoše Mountains and Šumava Mountains, where no airborne data was registered.
- z leteckého geomagnetického mapování ČR v měřítku 1 : 25 000 od roku 1960 (ca 85 % celého území);
- zbytek území je pokryt měřítem 1 : 200 000 z předcházejících etap (1958-1960).