| Parameter |
Data
Type |
Description |
Default |
Unpolarized_Phase_Function:
This model is a completely depolarizing phase function.
|
| phase_function |
Phase_Function_Ptr |
The scalar part of the phase function. |
Henyey_Greenstein_Phase_Function |
| log_absorption |
double |
The natural logarithm of the Naperian absorption coefficient [1/µm]. |
-20 |
| log_scattering |
double |
The natural logarithm of the Naperian scattering coefficient [1/µm]. |
0 |
CodeWhitney_Phase_Function:
The phase function defined by Code and Whitney [A.D. Code and B.A. Whitney, "ePolarization from scattering in blobs,"e;
Astrophysical Journal 441, 400-407 (1995)], adapted to allow for any scalar phase function. That is, the polarized phase function is
given by
\begin{equation}
{\bf P}(\theta)=p(\theta)\times\left(
\begin{array}{cccc}
1 & - p_l \sin^2\theta-1)/(1+\cos^2\theta) & 0 & 0 \\
- p_l \sin^2\theta-1)/(1+\cos^2\theta) & 1 & 0 & 0 \\
0 & 0 & 2 \cos\theta/(1+\cos^2\theta) & p_c \sin\theta_f/(1+\cos^2\theta_f) \\
0 & 0 & - p_c \sin\theta_f/(1+\cos^2\theta_f) & 2 \cos\theta/(1+\cos^2\theta)
\end{array}\right)
\end{equation}
where $p(\theta)$ is the scalar phase function, $\theta_f = \theta [1+3.13 s \exp(-7\theta/\pi)]$, and $p_l$, $p_c$, and $s$ are parameters.
|
| phase_function |
Phase_Function_Ptr |
The scalar part of the phase function. |
Henyey_Greenstein_Phase_Function |
| log_absorption |
double |
The natural logarithm of the Naperian absorption coefficient [1/µm]. |
-20 |
| log_scattering |
double |
The natural logarithm of the Naperian scattering coefficient [1/µm]. |
0 |
| plmax |
double |
The maximum degree of linear polarization, $p_l$. |
1 |
| pcmax |
double |
The maximum degree of circular polarization, $p_c$. |
0 |
| s |
double |
The circular polarization asymmetry parameter, $s$. |
0 |
Constrained_Phase_Function:
The phase function defined by Germer [T.A. Germer, "e;Polarized single-scattering phase function determined
for a common reflectance standard from bidirectional reflectance
measurements,"e; Proc. SPIE 10655, 1065504 (2018)]. It defines values for the polarized part of the phase function at
0°, 60°, 120°, and 180°, imposing requirements in the forward and backward scattering direction, and performing
a cubic spline for all other angles. The phase function is given by
\begin{equation}
{\bf P}(\theta)=p(\theta)\times\left(
\begin{array}{cccc}
1 & m_{01} & 0 & 0 \\
m_{01} & m_{11} & 0 & 0 \\
0 & 0 & m_{22} & m_{23} \\
0 & 0 & -m_{23} & m_{33}
\end{array}\right)
\end{equation}
|
| phase_function |
Phase_Function_Ptr |
The scalar part of the phase function. |
Henyey_Greenstein_Phase_Function |
| log_absorption |
double |
The natural logarithm of the Naperian absorption coefficient [1/µm]. |
-20 |
| log_scattering |
double |
The natural logarithm of the Naperian scattering coefficient [1/µm]. |
0 |
| m11_0 |
double |
The value of $m_{11}$ and $m_{22}$ at $\theta = 0^\circ$. |
1 |
| m11_60 |
double |
The value of $m_{11}$ at $\theta = 60^\circ$. |
0 |
| m11_120 |
double |
The value of $m_{11}$ at $\theta = 120^\circ$. |
0 |
| m11_180 |
double |
The value of $m_{11}$ and $-m{22}$ at $\theta = 180^\circ$. |
0 |
| m22_60 |
double |
The value of $m_{22}$ at $\theta = 60^\circ$. |
0 |
| m22_120 |
double |
The value of $m_{22}$ at $\theta = 120^\circ$. |
0 |
| m33_0 |
double |
The value of $m_{33}$ at $\theta = 0^\circ$. |
1 |
| m33_60 |
double |
The value of $m_{33}$ at $\theta = 60^\circ$. |
1 |
| m33_120 |
double |
The value of $m_{33}$ at $\theta = 120^\circ$. |
1 |
| m33_180 |
double |
The value of $m_{33}$ at $\theta = 180^\circ$. |
1 |
| m10_60 |
double |
The value of $m_{10}$ at $\theta = 60^\circ$. |
0 |
| m10_120 |
double |
The value of $m_{10}$ at $\theta = 120^\circ$. |
0 |
| m23_60 |
double |
The value of $m_{23}$ at $\theta = 60^\circ$. |
0 |
| m23_120 |
double |
The value of $m_{23}$ at $\theta = 120^\circ$. |
0 |
SphericalScatterer_Phase_Function:
This model uses a SphericalScatterer to determine the phase function.
|
| scatterer |
SphericalScatterer_Ptr |
The model for a spherical scatterer. |
MieScatterer |
| volume_density |
double |
The volume number density of scatterers [&\micro;m-3]. |
1E-4 |
Distributed_Mie_Phase_Function:
This model averages the Mie scattering function over a distribution of sphere sizes to determine the phase function.
|
| lambda |
double |
The wavelength of the light in vacuum. |
0.532 |
| medium |
dielectric_function |
The optical constants of the medium surrounding the spheres, expressed as a complex number (n,k) or, optionally, as a function of wavelength. |
0.532 |
| sphere |
dielectric_function |
The optical constants of the spheres, expressed as a complex number (n,k) or, optionally, as a function of wavelength. |
0.532 |
| distribution |
VolumeParticleSizeDistribution_Ptr |
The diameter distribution and number of spheres. |
VolumeParticleSizeDistribution |
| integralStart |
double |
The starting diameter for the integral over diameter [µm]. |
0.1 |
| integralEnd |
double |
The ending diameter for the integral over diameter [µm]. |
100 |
| integralStep |
double |
The fractional step diameter for integration. (The integral is performed logarithmically.) |
0.01 |