Along-beam velocity fluctuation

Methods to compute the along-beam velocity fluctuation, [math]\displaystyle{ b^{\prime} }[/math] :

1. If using burst sampling, calculations are done over the length of the burst or some sub-period over which the turbulent flow statistics can assumed to be stationary
2. If using continuous sampling, calculations are done over segments with a duration over which the turbulent flow statistics can assumed to be stationary
3. For each data segment consisting of N profiles (i.e. [math]\displaystyle{ t_s }[/math]), the turbulent fluctuations are calculated separately for each beam and bin by either:
   • The mean over the data segment
   • A linear detrend of the segment
   • A low pass filtered signal