SCATMECH > Classes and Functions > Surface Scattering Models > Subsurface_Particle_BRDF_Model

class Subsurface_Particle_BRDF_Model

The class Subsurface_Particle_BRDF_Model calculates the scattering by a particle beneath a surface and embedded within a non-absorbing medium. The model uses a ray-tracing approximation and ignores any interaction of the particle with its image in the surface.

Diagram showing the components contributing to the effective BRDF of a sample surrounded by air.

Parameters:

Parameter	Data Type	Description	Default
lambda	double	Wavelength of the light in vacuum [µm]. (Inherited from BRDF_Model.)	0.532
type	int	Indicates whether the light is incident from above the substrate or from within the substrate and whether the scattering is evaluated in reflection or transmission. The choices are: 0 : Light is incident from the above the substrate, and scattering is evaluated in reflection. 1 : Light is incident from the above the substrate, and scattering is evaluated in transmission. 2 : Light is incident from the within the substrate, and scattering is evaluated in reflection. 3 : Light is incident from the within the substrate, and scattering is evaluated in transmission. For 1, 2, and 3, the substrate must be non-absorbing. (Inherited from BRDF_Model).	0
substrate	dielectric_function	The optical constants of the substrate, expressed as a complex number (n,k) or, optionally, as a function of wavelength. The substrate for this model must be non-absorbing. (Inherited from BRDF_Model.)	(4.05,0.05)
density	double	The surface number density of local scatterers [µm^-2]. (Inherited from Local_BRDF_Model.)	1
stack	StackModel_Ptr	Description of any stack of films deposited on the substrate.	No_StackModel
depth	double	The distance from the surface to the center of the particle [µm]. This parameter should be at least as large as the radius of particle, if the particle is spherical.	0
scatterer	Free_Space_Scatterer_Ptr	The model describing the scattering by a particle. The medium surrounding the sphere (`scatterer.medium`) must be the same as the substrate (`substrate`), and the wavelength (`scatterer.lambda`) must match the wavelength (`lambda`).	MieScatterer
alpha	double	The rotation of the particle about the z-axis [rad]. This parameter only has an effect if the particle is non-axially symmetric. (Note that all models currently inheriting Free_Space_Scatterer are axially symmetric.)	0
beta	double	The rotation of the particle about the y-axis [rad]. This rotation follows the rotation alpha about the z-axis. This parameter only has an effect if the particle is non-spherical. To further rotate the particle about the z-axis after rotation about the y-axis, the user should evaluate the scattering in a rotated geometry.	0

Include file:

#include "subsphere.h"

Source code:

subsphere.cpp

Definition of public elements:

class Subsurface_Particle_BRDF_Model 
        : public Local_BRDF_Model
{
};

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