Precise tune measurements from multiple beam position monitors

One of the main limitations for precise tune measurements using kicked turn-by-turn data is the beam decoherence, which can limit the available signal to a reduced number of turns. Applying Laskar´s frequency analysis, on measurements from several beam position monitors, a fast and accurate determination of the real tune is possible. The efficiency of the method is demonstrated when applied in turn-by-turn data from the ESRF storage ring and CERN´s super proton synchrotron. Estimates from tracking simulations and analytical considerations are further compared with the experimental results.