Name:
sf_spectrum.pro
Purpose:
Calculate the structure function spectrum and the corresponding inertial range indices.
Calling sequence:
sf_spectrum,c_img,q,rd,Sf,zq,err_zq,bz_thres=bz_thres,xpos=xpos,ypos=ypos,xneg=xneg,yneg=yneg,default_rd=default_rd,default_q=default_q,manual_index=manual_index,auto_index=auto_index,help=help
Input parameters:
c_img: Br or Blos HARP cutout magnetogram or Btot, corrected for limb presence. Blos cutout should be deprojected.
q: The array of selectors (normally positive real numbers excluding 0)
rd: The array of displacement magnitudes, in units of pixel size (a sufficient dynamical range of two or more orders of magnitude is required)
Keyword:
bz_thres: threshold to the magnetic flux
/xpos: The displacement vector is oriented toward positive x-axis values
/xneg: The displacement vector is oriented toward negative x-axis values
/ypos: The displacement vector is oriented toward positive y-axis values
/yneg: The displacement vector is oriented toward negative y-axis values
/default_q: Set to use the default values for q as follows: q in (0.5,8) with step 0.5
/default_rd: Set to use the default values for rd as follows: rd in (1,300) pixels with step=1 between (1,10) step=5 between (15,100) step=10 between (110,300)
/manual_index: If set, the exponents zq and their errors err_zq are found interactively, by manually choosing the extrema of the power-law regime
/auto_index: If set, the exponents zq and their errors err_zq are found automatically, via a detection of the power-law regime
/help: Use alone to obtain the above information
Output:
Sf: Array [n(q),n(rd)] where n(q), n(rd) are the number of elements of q and rd arrays respectively. It provides the structure function value for each q and rd
zq: Array [n(q)] of the structure function exponents for each q provided by power-law fitting between Sf(q,*) and rd(*)
err_zq: Uncertainties associated with each zq value
Property name in DB:
sfunction_Blos.zq. sfunction_Blos.zq_err, sfunction_Blos.q, sfunction_Blos.sf, sfunction_Blos.rd
sfunction_Br.zq. sfunction_Br.zq_err, sfunction_Br.q, sfunction_Br.sf, sfunction_Br.rd
sfunction_Btot.zq. sfunction_Btot.zq_err, sfunction_Btot.q, sfunction_Btot.sf, sfunction_Btot.rd
Repository:
https://dev.flarecast.eu/stash/projects/FE/repos/sfunction-idl/browse
References:
V. I. Abramenko, et al. 2002, The Astrophysical Journal, 577, 487
Georgoulis 2005, Solar Physics, 228, 5
Georgoulis M.K., 2012, Solar Physics, 276,161