Abstract class Axisymmetric_Shape
The abstract class Axisymmetric_Shape is used by TMatrix_Axisymmetric_Scatterer and Axisymmetric_Particle_BRDF_Model to describe the shape of a particle having a vertical axis of rotation.
Instantiable Models and Their Parameters:
| Parameter | Data Type | Description | Default |
|---|---|---|---|
Ellipsoid_Axisymmetric_Shape:
An oblate or prolate ellipsoidal particle.
|
|||
| npts | int | The
number of sampled points of the shape needed for the
line integrals in the T-Matrix calculation. This value should be significantly larger than the polar order of the calculation. (Inherited from Axisymmetric_Shape.) |
100 |
| vertical | double | The length of the vertical semi-axis of the ellipsoid [µm]. | 0.05 |
| horizontal | double | The length of the horizontal semi-axis of the ellipsoid [µm]. If horizontal > vertical, then the ellipsoid is oblate. If horizontal < vertical, then the ellipsoid is prolate. | 0.05 |
| offset | double | Origin offset for the calculation [µm]. Changing the origin should not have an effect on the scattered intensity, but will change the convergence properties of the calculation. A positive value corresponds to the origin moving closer to the surface, when using one of the surface scattering models. | 0 |
Cylinder_Axisymmetric_Shape:
A right circular cylinder with optionally rounded
corners.
|
|||
| npts | int | The
number of sampled points of the shape needed for the
line integrals in the T-Matrix calculation. This value should be significantly larger than the polar order of the calculation. (Inherited from Axisymmetric_Shape.) |
100 |
| radius | double | The radius of the cylinder [µm]. | 0.05 |
| length | double | The length of the cylinder [µm]. | 0.1 |
| corner | double | The radius of curvature of the corners [µm]. | 0 |
| renorm | int | If this parameter is non-zero, then the volume of the particle is renormalized to that of a cylinder with corner equal to zero. | 0 |
Conical_Axisymmetric_Shape:
A right circular cone with optionally rounded
corners.
|
|||
| npts | int | The
number of sampled points of the shape needed for the
line integrals in the T-Matrix calculation. This value should be significantly larger than the polar order of the calculation. (Inherited from Axisymmetric_Shape.) |
100 |
| radius | double | The radius of the base of the cone [µm]. | 0.05 |
| height | double | The height of the cone [µm]. | 0.1 |
| offset | double | By default, the origin of the particle is positioned at one-third of its height. To change the location of the origin, set the value of offset to a non-zero value [µm]. If this position is positive, the origin is moved towards the base of the cone. Changing the origin should not have an effect on the scattered intensity, but will change the convergence properties of the calculation. | 0 |
| corner_base | double | The radius of curvature of the corners at the base of the cone [µm]. | 0 |
| corner_apex | double | The radius of curvature of the apex of the cone [µm]. | 0 |
| updown | int | If this parameter is zero, the cone is pointing up (positive z-direction). If this parameter is non-zero, it is pointing down. | 0 |
| renorm | int | If this parameter is non-zero, then the volume of the particle is renormalized to that of a cone with corner_base and corner_apex set to zero. | 0 |
Double_Conical_Axisymmetric_Shape:
A particle having a diamond-shaped cross section,
with optionally rounded corners.
|
|||
| npts | int | The
number of sampled points of the shape needed for the
line integrals in the T-Matrix calculation. This value should be significantly larger than the polar order of the calculation. (Inherited from Axisymmetric_Shape.) |
100 |
| height | double | The total height of the particle [µm]. | 0.1 |
| radius | double | The radius at the waist of the particle [µm]. | 0.05 |
| corner_apex | double | The radius of curvature of the corners at the apexes of the particle [µm]. | 0 |
| corner_waist | double | The radius of curvature of the waist of the cone [µm]. | 0 |
| renorm | int | If this parameter is non-zero, then the volume of the particle is renormalized to that of a double-cone with corner_waist and corner_apex set to zero. | 0 |
Chebyshev_Axisymmetric_Shape:
An axisymmetric shape whose radial function (radius
as a function of angle theta) is that of an
ellipsoid, multiplied by the factor
(1+amplitude*cos(n*theta)). This implementation
allows a fraction of the ellipsoid to be unperturbed,
in a manner which keeps the derivative of the radial
function continuous.
|
|||
| npts | int | The
number of sampled points of the shape needed for the
line integrals in the T-Matrix calculation. This value should be significantly larger than the polar order of the calculation. (Inherited from Axisymmetric_Shape.) |
100 |
| vertical | double | The length of the vertical semi-axis of the ellipsoid [µm]. | 0.05 |
| horizontal | double | The length of the horizontal semi-axis of the ellipsoid [µm]. If horizontal > vertical, then the ellipsoid is oblate. If horizontal < vertical, then the ellipsoid is prolate. | 0.05 |
| amplitude | double | The relative amplitude of the oscillations. | 0.01 |
| n | int | The number of half-cycles. | 8 |
| start | double | The angle [rad] at which the oscillations begin. | 0 |
| end | double | The angle [rad] at which the oscillations end. | 3.14159265 |
| renorm | int | If this parameter is non-zero, then the volume of the particle is renormalized to that of the ellipsoid with amplitude set to zero. | 0 |
Indented_Ellipsoid_Axisymmetric_Shape:
An indented ellipsoidal particle.
|
|||
| npts | int | The
number of sampled points of the shape needed for the
line integrals in the T-Matrix calculation. This value should be significantly larger than the polar order of the calculation. (Inherited from Axisymmetric_Shape.) |
100 |
| vertical | double | The length of the vertical semi-axis of the ellipsoid [µm]. | 0.05 |
| horizontal | double | The length of the horizontal semi-axis of the ellipsoid [µm]. If horizontal > vertical, then the ellipsoid is oblate. If horizontal < vertical, then the ellipsoid is prolate. | 0.05 |
| indent | double | The depth of the indentation [µm]. | 0.01 |
| updown | int | (0) if the flat indentation is down (towards the surface) or (1) if the flat is up. | 0 |
| renorm | int | (0) if the particle dimensions are held fixed or (1) if the particle volume is to be renormalized to the volume of the un-indented ellipse. | 0 |
Table_Axisymmetric_Shape:
A shape specified by a table of values, radius versus
angle [deg], usually specified by a file.
|
|||
| npts | int | The
number of sampled points of the shape needed for the
line integrals in the T-Matrix calculation. This value should be significantly larger than the polar order of the calculation. (Inherited from Axisymmetric_Shape.) |
100 |
| table | Table | The table containing the radius versus angle [deg]. | 0.05 |
| scale | double | If scale is negative, the particle's size is renormalized so that its volume is that of a sphere having a radius abs(scale). If scale is positive, then the radius from the table is multiplied by scale to obtain the radius used. if this parameter is zero, then the size of the particle is not renormalized. | 1 |
See also:
SCATMECH Home, Conventions, TMatrix_Axisymmetric_Scatterer, Axisymmetric_Particle_BRDF_Model
Include file:
#include "tmatrix.h"
Source code:
axisym.cpp
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Current SCATMECH version: 7.22 (April 2021)