I'm starting hydraulic experiments, where I'd have to measure velocity in an unsteady flow with a device called Acoustic Doppler Velocimeter (acquisition rate: 100 Hz) . In DSP terms, I'd have a nonstationary signal in a shape of waves (https://imgur.com/a/Qd72HjO for streamwise velocity (first curve) with 2 waves). This signal contains the mean component (mean velocity) and noise (turbulence). My goal is to extract the mean velocity.
I have looked up DSP and found many interesting models (Huang-Hilbert Transform, Wavelet Transform, Short Fourier Transform) to denoise. The only problem is that, in steady case, they need about 3 minutes measuring in one point so that they can average (arithmetic averaging) and filter out this noise. Since I'm in unsteady, I'd probably need more. Besides, my signal lasts about 1.5 minute. So I'm a little bit lost: can I still apply the denoising models (They're applied in the literature) ?