Name:

alpha_exp_fft.pro

Purpose:

Calculate 

Calling sequence:

ALPHA_EXP_FFT, img, ind, bin, range, linfit_params

Input parameters:

img = Br, Blos, or Btot HARP cutout magnetogram corrected for limb presence.

ind = structure containing magnetogram's metada (resolution).

bin = Number of bins values in k-space for calculating the 1D PSD from the 2D PSD (angle integration). Optimal value for computation time/goo fit is 900

range = definition of the Inertial range for linear fit in units of Mm^-1 . Default values are 0.05 to 0. (or 2 - 20 Mm in linear size)

Optional input parameters:

None

Output parameters:

linfit_params - 3 elements 1D array containing the resulting parameters from the linear fit of PSD(k).

                 linfit_params[0] = slope of the linear fit (alpha exponent)

                 linfit_params[1] = 1-sigma error associated to the slope

                 linfit_params[2] = goodness-of-fit parameter value.         

Property name in DB:

alpha_exp_fft_blos, alpha_exp_fft_br, alpha_exp_fft_btot

alpha_exp_fft_blos.alpha, alpha_exp_fft_blos.sigma, alpha_exp_fft_blos.fit_r

Repository:

https://dev.flarecast.eu/stash/projects/FE/repos/alpha_exp_fft-idl/browse

References

1. http://dx.doi.org/10.1086/431732
2. http://adsabs.harvard.edu/abs/2015SoPh..290..335G