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Name:
calc_sharp_params.pro
Purpose:
SHARP params This algorithm reproduces the 16 SHARP parameters included in the FITS headers metadata. These parameters, are described in Table 1 of Bobra et al. 2014. It also expands on the SHARP keywords to calculate other (spatial) distribution moments of the physical quntity: minimum and maximum values, mean, median, total, and other distribution moments such as the standard deviation (σ), skewness (ς), and kurtosis (κ). A good-pixels mask is used as well. In contrast to the original algorithm -- which uses a Green-function solver to calculate the surface potential field extrapolation -- the much faster FFT approach developed by Alissandrakis 1981 is used.
Calling sequence:
CALC_SHARP_PARAMS, images, ind, params_out [, act_kws]
Input parameters:
images = HARP cutout magnetogram corrected for limb presence.
ind = structure containing magnetogram's metada (resolution).
Optional input parameters:
act_kws = Optional keywords. Setup in the configuration files. Output parameters:
params_out - 3Structure elementscontaining 1Dthe arrayresults. containingThere theare resulting16 parameterskey fromnames the(one linearfor fiteach ofproperty PSD(kmap).
and for most of them 9 sub key values are calculated: total, mean, median, standard
linfit_params[0] = slope of the linear fit (alpha exponent) deviation, skewness, kurtosis, min, and max.
Key linfit_params[1] = 1-sigma error associated to the slopenames: usflx, sflux, gamma, hgradbt, hgradbz, hgradbh, jz, usiz, twistp, hz, ushz,
linfit_params[2] = goodness-of-fit parameter value snetjzpp*, rhod, rho, sheargamma, ggt45fract**.
Sub-keys: total, ave, stddev, median, max, skewness, kurtosis.*Only total sub-key.**Only the fraction value, no sub-key. 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_rsharp_kw.keyname.subkeyname
E.g.: sharp_kw.usflux.total For total unsigned flux.
Repository:
https://dev.flarecast.eu/stash/projects/FE/repos/sharp_kw-idl/browse
References
- http://dx.doi.org/10.1086/431732http://adsabs.harvard.edu/abs/2015SoPh2014SoPh..290289..335G3549B