Forward-difference: Difference between revisions

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See [[Example forward-difference | example forward-difference calculation]] for more detail regarding the calculation
See [[Example forward-difference | example forward-difference calculation]] for more detail regarding the calculation


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Return to [[Processing your ADCP data using structure function techniques | Compute structure functions and dissipation estimates]]


Return to [[Processing your ADCP data using structure function techniques | Compute structure functions and dissipation estimates]]
[[Category:Velocity profilers]]

Revision as of 16:02, 23 November 2021

For the forward-difference scheme

  1. start with n being the lowest number bin of the range over which the structure function is to be evaluated (number of bins in range should equal or exceed nrmax) + 1
    1. start with δ=1
    2. compute the second order forward-difference structure function D(n,δ) as the segment mean of the square of the velocity difference between the bin n and bin n+δ:

      D(n,δ)=[v(n,t)v(n+δ, t)]2

      where the angled brackets indicate the mean across all t for the data segment yielding a velocity difference after the application of the Level 1 QC criteria
    3. increment δ and repeat steps until δ=nrmax or n+δ exceeds the last bin of the range over which the structure function is to be evaluated
  2. increment n and repeat steps until n+1 is the last bin of the range over which the structure function is to be evaluated

See example forward-difference calculation for more detail regarding the calculation


Return to Compute structure functions and dissipation estimates