lightscatpro5.htm

球形粒子Mie 散射用Matlab编写的Mie theory计算程序。在光子学中运用广泛

 <tr>
<td>e1 </td><td> T11 </td><td> T12 </td><td> T13 </td><td>T14 </td><td>  e1 </td>
 </tr><tr> 
<td>e2 </td><td> T21 </td><td> T22 </td><td> T23 </td><td> T24 </td><td> e2 </td>
 </tr><tr>
<td>o1 </td><td> T31 </td><td> T32 </td><td> T33 </td><td> T34 </td><td> m1 </td>
 </tr><tr> 
<td>o2 </td><td> T41 </td><td> T42 </td><td> T43 </td><td> T44 </td><td> m2 </td>
</tr>
</table>
 
<p><strong>Structures des coefficients de d&eacute;composition des ondes</strong> <br>
Les champs incident, diffus&eacute; et interne &agrave; la sph&egrave;re sont d&eacute;compos&eacute;s sur une base de fonctions vectorielles sph&eacute;riques. Ces structures contiennent ces coeffcients de d&eacute;composition. 
<table width="884" border="1">
 <tr>
  <td><strong>structure </strong></td>
  <td><strong> description </strong></td>
  </tr><tr> 
  <td> P_i </td>
  <td> coefficients of the incident field </td>
  </tr><tr> 
  <td>P_s </td>
  <td> coefficients of the scattered field </td>
  </tr><tr> 
  <td>P_o </td>
  <td> coefficients of field inside the sphere </td>
</tr>
</table>

<p> Les variables des 3 structures sont o1, o2, e1 and e2. Chaque variable (exemple P_i.o) peut &ecirc;tre un scalaire, un vecteur ou une matrice selon le cas &eacute;tudi&eacute;. Dans le cas g&eacute;n&eacute;ral (matrice) les variables d&eacute;pendent de l et m </p> 
<p><strong>Structure &quot;space&quot;</strong><br>
Cette structure contient les variables d&eacute;crivant la zone spatiale o&ugrave; le champ &eacute;lectromagn&eacute;tique va &ecirc;tre &eacute;tudi&eacute;. </p>
<table width="884" border="1">
 <tr>
<td>  Name </td><td> description </td><td>  </td></tr><tr>
<td>  xmin </td><td> describes the studied windows in pixels </td><td> integer </td></tr><tr>
<td>  xmax </td><td> describes the studied windows in pixels </td><td> integer </td></tr><tr>
<td>  ymin </td><td> describes the studied windows in pixels </td><td> integer </td></tr><tr>
<td>  ymax </td><td> describes the studied windows in pixels </td><td> integer </td></tr><tr>
<td>  unit\_x </td><td> real size of one pixel in horizontal direction </td><td> number </td></tr><tr>
<td>  unit\_y </td><td> real size of one pixel in vertical direction </td><td> number </td></tr><tr>
<td>  X </td><td> real horizontal coordinates </td><td> matrix </td></tr><tr>
<td>  Y </td><td> real vertical coordinates </td><td> matrix </td></tr><tr>
<td>  phi </td><td> \varphi positions of the studied points </td><td> number or matrix </td></tr><tr>
<td>  theta </td><td> \theta positions of the studied points </td><td> number or matrix </td></tr><tr>
<td>  RR </td><td> radius of the studied points </td><td> number or matrix </td></tr><tr>
<td>  Ntheta </td><td> number of \theta angles </td><td> integer </td></tr><tr>
<td>  Nphi </td><td> number of \varphi angles </td><td> integer </td></tr><tr>
<td>  alpha </td><td> angle of point in a selected plane </td><td> number or matrix </td></tr><tr>
<td>  alphamin </td><td> minimum value of the alpha angle </td><td> number </td></tr><tr>
<td>  alphamax </td><td> maximum value of the alpha angle </td><td> number </td></tr><tr>
<td>  taille\_i </td><td> horizontal size of the coordinates matrix </td><td> integer </td></tr><tr>
<td>  taille\_J </td><td> vertical size of the coordinates matrix </td><td> integer </td></tr><tr>
<td>  lieu </td><td> 1 where the field must computed 0 elsewhere </td><td> matrix </td></tr><tr>
<td>  Mx </td><td> label of the horizontal axis </td><td> vector </td></tr><tr>
<td>  My </td><td> label of the vertical axis </td><td> vector </td></tr><tr>
<td>  title </td><td> kind of field: incident, scattered or total </td><td> string </td></tr><tr>
<td>  symetrie </td><td> 1: the field in the symmetric plane is computed </td><td> 0/1 </td></tr><tr>
<td>  sphere </td><td> choice to plot the sphere around the aggregate </td><td> 0/1 </td></tr><tr>
<td>  inclinaison </td><td> angle used to described the studied plane </td><td> number</td>
 </tr>
</table>

<p><strong>Structure &quot;post&quot;</strong><br>
Cette structure contient les variables d&eacute;crivant quels post-traitements doivent &ecirc;tre effectu&eacute;s. </p>
<table width="884" border="1">
 <tr>
<td> </td><td> values </td><td> description </td></tr><tr>
<td>  composante </td><td> (0/1) </td><td> plot the 6 components of electromagnetic field </td></tr><tr>
<td>  poynting </td><td> (0/1) </td><td> plot the components of the Poynting vector </td></tr><tr>
<td>  stokes2d </td><td> (0/1) </td><td> plot the Stokes elements in a plane (x,y) </td></tr><tr>
<td>  stokes1d </td>
<td> 0-&gt;4 </td><td> 0/ 1: Stokes elements(\alpha) 2:idem (\theta,\varphi) </td></tr><tr>
<td> </td><td> </td><td> 3: Stokes elements(x,y)/ 4:idem in N points </td></tr><tr>
<td> section\_eff </td>
<td> 0-&gt;4</td><td> 0/ 1: extinction cross section/ 2: backscattering cross section </td></tr><tr>
<td> axespolar </td><td> (0/1) </td><td> choice to plot the axis of polarization </td></tr><tr>
<td> diagram </td>
<td> 0-&gt;2 </td><td> 0/ 1:choice to plot the phase function F(\alpha) 2: idem with F(\varphi,\theta) </td></tr><tr>
<td> coord </td>
<td> 0-&gt;3 </td><td> 0: no view/ 1: view in spherical coordinates/ </td></tr><tr>
<td> </td><td> </td><td> 2: view in cartesian coordinates/ 3:view of the absolute value </td></tr><tr>
<td>onde </td>
<td> 1-&gt;3 </td><td> studied field 1: scattered/ 2: incident/ 3: total </td></tr><tr>
<td> espace </td>
<td> 1-&gt;13 </td><td> kind of studied space area </td></tr><tr>
<td> choixexploitation </td><td> (0/1) </td><td> choice to execute the post treatment</td>
</tr>
</table>

<p><em>Post.espace=space.espace</em> peuvent prendre plusieurs valeurs : 
<table width="884" border="1">
 <tr>
<td>  space </td><td> description </td></tr><tr>
 <td> 1 </td><td> half-plane containing Oz axis and defined by \varphi </td></tr><tr>
<td>  2 </td><td> angular variation in the half-plan containing Oz axis and defined by \varphi </td></tr><tr>
<td>  3 </td><td> R constant and variation as a function of (\theta,\varphi) </td></tr><tr>
<td>  4 </td><td> N points (R_N,\theta_N,\varphi_N) </td></tr><tr>
<td>  5 </td><td> half-plane (X,Y) </td></tr><tr>
<td>  6 </td><td> the studied space is defined out of the programm </td></tr><tr>
<td>  7 </td><td> half-plane containing Oy axis and defined by the angle (Oz,u) </td></tr><tr>
<td>  9 </td><td> angular variation in the plane containing Ox axis and defined by angle (Oz,u)</td></tr><tr>
<td>  10 </td><td> half-plane containing Ox axis and defined by angle (Oz,u) </td></tr><tr>
<td>  11 </td><td> R=R_o and angular variation in the plane containing Oy axis </td></tr><tr>
<td> </td><td> and defined by angle (Oz,u) </td></tr><tr>
<td>12 </td><td> study in the backward direction </td></tr><tr>
<td>13 </td><td> study in the forward direction </td>
</tr>
</table>

<p><strong>Structure &quot;champ&quot;</strong><br>
Cette structure contient les valeurs du champ &eacute;lectromagn&eacute;tique dans l'espace &eacute;tudi&eacute;.</p>
<table width="884" border="1">
 <tr>
<td> Name </td><td> format </td><td> description </td></tr><tr>
<td>  Er </td><td> matrix </td><td> r component of electric field </td></tr><tr>
<td>  Et </td><td> matrix </td><td> \theta component of electric field </td></tr><tr>
<td>  Ep </td><td> matrix </td><td> \varphi component of electric field </td></tr><tr>
<td>  Hr </td><td> matrix </td><td> r component of magnetic field </td></tr><tr>
<td>  Ht </td><td> matrix </td><td> \theta component of magnetic field </td></tr><tr>
<td>  Hp </td><td> matrix </td><td> \varphi component of magnetic field </td>
</tr>
</table>
  
<p><strong>Structure &quot;result&quot;</strong><br>
Cette structure contient les variables concernant les propri&eacute;t&eacute;s physiques du champ dans l'espace</p>
<table width="884" border="1">
 <tr>
<td> Name </td><td> description </td></tr><tr>
<td>  poynting_r </td><td> r component of the Poynting vector </td></tr><tr>
<td>  poynting_t </td><td> \theta component of the Poynting vector </td></tr><tr>
<td>  poynting_p </td><td> \varphi component of the Poynting vector </td></tr><tr>
<td>  poynting </td><td> Absolute value of the Poynting vector </td></tr><tr>
<td>  phase_fct </td><td> Phase function </td></tr><tr>
<td>  Csca </td><td> Scattering cross section </tr><tr>
<td>  S0, S1, S2, S3 </td><td> The 4 Stokes elements </td></tr><tr>
<td>  degreP </td><td> Polarization degree </td></tr><tr>
<td>  Ex, Ey, Ez </td><td> Component of electric field in cartesian </td></tr><tr>
<td>  Hx, Hy, Hz </td><td> Component of magnetic field in cartesian </td></tr><tr>
<td>  NormeE </td><td> Absolute value of the electric field </td>
</tr>
</table>

<p><a name="rep"></a>7) Contenus des diff&eacute;rents r&eacute;pertoires<br>
  ______________________________<br>
  - prog : r&eacute;pertoire qui contient les programmes de base de l'algorithme<br>
  - scripts : r&eacute;pertoire qui contient des scripts utilisant les programmes sans utiliser<br>
  les interfaces et ayant pour but de faire des &eacute;tudes particulires. ex :courbes de diffusion <br>
  - DescriptionAgregats : contient des exemples fichiers d&eacute;crivant des agr&eacute;gats et pouvant &ecirc;tre appel&eacute;s dans l'interface
  <br>
  - OndesIncidentes :
contient des exemples fichiers d&eacute;crivant l'onde incident et pouvant &ecirc;tre appel&eacute;s dans l'interface </p>
<p>- old : anciens programmes pas encore jet&eacute;<br>
</p>
<p><a name="rmq"></a>8) Remarques :<br>
  ______________<br>
  - Programmes ecrits sous matlab 6.5 sous le syst&egrave;me d'exploitation XP pro (microsoft). Pas de compilation n&eacute;cessaire. <br>
  - Interfaces g&eacute;n&eacute;r&eacute;es par &quot;guide&quot; sous Malab. Peut poser probl&egrave;me sous les autres versions de Matlab. <br>
  - Pour utiliser les programmes sans passer par les interfaces, entrer les donn&eacute;es d&eacute;crivant le probl&egrave;me dans le fichier donnees.m et lancer le programme &quot;T1.m&quot;.<br>
  - Pour avoir plus d'infos sur le fonctionnement de n'importe quel fichier .m utiliser la commande matlab &quot;help nom_fichier&quot;.<br>
  -
  En cas de probl&egrave;me, un protocole de tests existe : <a href="./prog/TestProg.htm">TestProg.htm</a>.<br>
  - Pour en savoir plus <a href="maito:[e-mail]">[e-mail]</a>.<br>
  - L'&eacute;volution temporelle  a &eacute;t&eacute; choisie &eacute;gale &agrave; exp(-iwt).<br>
  - Des codes en Fortran de l'algorithme de la T-matrice sont mis &agrave; disposition par Mishchenko sur <a href="http://www.giss.nasa.gov/%7Ecrmim/t_matrix.html">http://www.giss.nasa.gov/~crmim/t_matrix.html</a></p>
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