A robust phase measurement method to detect self-mixing signals from rough surface targets is ad-dressed. Using the Hilbert transform to create the analytic signal of the monitored optical output power, an accurate instantaneous phase can be extracted without being affected by amplitude varia-tions induced by speckle phenomenon. In case of fringe fading, a running average filter removes the local bias offset improving the calculations. This also allows to observe the phase at dynamic feedback levels within the same calculation, avoiding the need of adding external optical, mechanical or elec-tronic components. This method provides confidence for fringe detection required in subsequent steps to reach sub-wavelength precision of a reconstructed displacement or for velocimetry applications.