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mie_1

PURPOSE ^

Rayleigh Approximation of Mie Efficiencies for given

SYNOPSIS ^

function result = mie_1(m, x, xmax)

DESCRIPTION ^

 Rayleigh Approximation of Mie Efficiencies for given 
 complex refractive-index ratio m=m'+im" 
 and size parameter x=k0*a, k0= wave number in ambient medium,  
 a=sphere radius using the low-frequency approximation of the 
 complex Mie Coefficients an and bn for n=1, p. 131 
 in Bohren and Huffman (1983) BEWI:TDD122.
 Result is m', m", x, efficiencies for extinction (qext), 
 scattering (qsca), absorption (qabs), backscattering (qb), 
 asymmetry parameter asy=<costeta> and qratio=qb/qsca.
 Uses the function "mieab_1" for the Mie Coefficient a1.
 C. M�zler, May 2002.

CROSS-REFERENCE INFORMATION ^

This function calls: This function is called by:

DOWNLOAD ^

mie_1.m

SOURCE CODE ^

0001 function result = mie_1(m, x, xmax)
0002 % Rayleigh Approximation of Mie Efficiencies for given
0003 % complex refractive-index ratio m=m'+im"
0004 % and size parameter x=k0*a, k0= wave number in ambient medium,
0005 % a=sphere radius using the low-frequency approximation of the
0006 % complex Mie Coefficients an and bn for n=1, p. 131
0007 % in Bohren and Huffman (1983) BEWI:TDD122.
0008 % Result is m', m", x, efficiencies for extinction (qext),
0009 % scattering (qsca), absorption (qabs), backscattering (qb),
0010 % asymmetry parameter asy=<costeta> and qratio=qb/qsca.
0011 % Uses the function "mieab_1" for the Mie Coefficient a1.
0012 % C. M�zler, May 2002.
0013 
0014 if x==0,
0015     result=[0 0 0 0 0 1.5];
0016 elseif x>xmax,
0017     result=[NaN, NaN, NaN, NaN, NaN, NaN];
0018 else,
0019     nmax=1; n=1; cn=2*n+1; x2=x*x;
0020     f=mieab_1(m,x);
0021     anp=real(f); anpp=imag(f);
0022     dn=cn.*anp;
0023     qabs=2*dn/x2;
0024     en=cn.*(anp.*anp+anpp.*anpp);
0025     qsca=2*en/x2;   
0026     qext=qabs+qsca;
0027     q=-cn.*f;
0028     qb=q*q'/x2;
0029     qratio=qb/qsca;
0030     result=[qext qsca qabs qb 0 qratio];
0031 end;

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