A modal analysis of tonal fan noise is applied to deceleration measurements collected during the European project TurboNoiseBB at the Anecom test facility. Measurement data are preprocessed using two approaches for order extraction, one based on angular resampling of signals and the other based on instantaneous extraction of the complex envelopes. The instantaneous modal content is then obtained using modal identification and results from both preprocessing methods are compared. The azimuthal mode content of the three first Blade Passing Frequencies (BPF) is obtained through an iterative Bayesian inverse approach. Particularly the modal spectrum for the second BPF shows an interesting pattern with peaks and troughs throughout the deceleration. It suggests that detected modes are influenced by the azimuthal distribution of probes.