The "Geophysical Instrument Pool Potsdam" (GIPP) of the GFZ has aquired a fiber-optic gyroscope which allows the highly accurate orientation of geophysical sensors. This gyroscope produced by the company IXSEA allows the orientation of sensors (relative to Earth's rotation axis) with a typical accuracy of 0.1° (secant latitude). The orientation of sensors using a magnetic compass usually suffers from magnetic deflections by metal parts (e.g. in buildings) and the magnetic declination which is locally and temporary variing. The use of the fiber-optic gyroscope avoids these pitfalls. The exact orientation of seismometers is for example essential for the analysis of seismic anisotropy.