Home > atmlab > mie > mie_beamefficiencyold.m

mie_beamefficiencyold

PURPOSE ^

Cumulative power (corresponds to the beam efficiency in

SYNOPSIS ^

function result = mie_beamefficiencyold(m, x, tetalimit, nsteps)

DESCRIPTION ^

 Cumulative power (corresponds to the beam efficiency in 
 antenna theory) scattered within a maximum scattering angle 
 (variable from 0 to pi) for Mie Scattering with
 complex refractive-index ratio m=m'+im", size parameters x=k0*a, 
 according to Bohren and Huffman (1983) BEWI:TDD122
 INPUT: 
 m, x: as usual
 tetalimit: maximum angle to be considered, in radians
 nsteps: number of angles to be considered
 C. M�zler, June 2003.

CROSS-REFERENCE INFORMATION ^

This function calls: This function is called by:

DOWNLOAD ^

mie_beamefficiencyold.m

SOURCE CODE ^

0001 function result = mie_beamefficiencyold(m, x, tetalimit, nsteps)
0002 
0003 % Cumulative power (corresponds to the beam efficiency in
0004 % antenna theory) scattered within a maximum scattering angle
0005 % (variable from 0 to pi) for Mie Scattering with
0006 % complex refractive-index ratio m=m'+im", size parameters x=k0*a,
0007 % according to Bohren and Huffman (1983) BEWI:TDD122
0008 % INPUT:
0009 % m, x: as usual
0010 % tetalimit: maximum angle to be considered, in radians
0011 % nsteps: number of angles to be considered
0012 % C. M�zler, June 2003.
0013 
0014 dteta=tetalimit/nsteps;
0015 xmin=dteta/pi;
0016 m1=real(m); m2=imag(m);
0017 nx=(1:nsteps); dteta=tetalimit/nsteps;
0018 teta=(nx-0.5).*dteta;
0019     for j = 1:nsteps, 
0020         u=cos(teta(j));
0021         a(:,j)=Mie_S12(m,x,u);
0022         SL(j)= real(a(1,j)'*a(1,j))/(pi*x^2);
0023         SR(j)= real(a(2,j)'*a(2,j))/(pi*x^2);
0024     end;
0025 st=2*pi*sin(teta);
0026 SSL=st.*SL;
0027 SSR=st.*SR;
0028 tetad=teta*180/pi;
0029 Q=mie(m,x);
0030 Qsca=Q(2);
0031 z=0.5*dteta*cumsum(SSL+SSR)/Qsca;
0032 semilogx(tetad/180,z,'r-')
0033 title(sprintf('Cumulative Fraction of Scattered Power: m=%g+%gi, x=%g',m1,m2,x))
0034 xlabel('Maximum Scattering Angle/180�'),
0035 axis([xmin, tetalimit/pi, 0, 1.1]);
0036 result=[teta; SSL; SSR; z]';

Generated on Mon 15-Sep-2014 13:31:28 by m2html © 2005