Method for calibrating a device with atomic operation

The method involves successively injecting current into electromagnetic coils (6-8), and measuring magnetic fields generated by the corresponding coils. Gain coefficients of the corresponding coils are determined, where each gain coefficient is a ratio between the corresponding magnetic field and the injected current. The coils are grouped in pairs. Currents are simultaneously injected into the coils of each pair. Magnetic fields generated by combination of currents are measured. An angle between the coils is determined from the measured magnetic fields, the gain coefficients and the currents.