Hapke¶

class sonic.Hapke¶

Bases: sonic.Reflectance

This software is made available under the MIT license. See SONIC/LICENSE for details.

Constructor Summary

Hapke(AL_ss, hapkeModelType, HFuncType, SSPF, varargin)¶

Instantiates a sonic Hapke object.

Inputs:

AL_ss (nxm double): Single-scattering albedo matrix.
hapkeModelType (1x1 string): Implementation type of Hapke model
HFuncType (1x1 string): Implementation type of
Chandrasekhar H-Function. Current supported inputs are:
“rational”

“linear”

“exact”
SSPF (1x1 string): Implementation type of
Single-Scattering Phase Function. Current supported inputs are:
“isotropic”

“Rayleigh”

“HG1”
varargin (nx1 double): scattering parameter (xi); ONLY REQUIRED FOR “HG1” SSPF

Outputs:

obj (1x1 sonic.Hapke): Hapke object.

Last revised: 10/4/2024 Last author: Jennifer Nolan

Property Summary

AL_ss¶: Albedo - Single Scattering (n x m) [0, 1]

AL_ssFlat¶: Albedo - Single Scattering (converted to vector for matrix math)

HFuncType¶: Type of H-function approximation: “exact”, “rational”, or “linear”

SSPF¶: Type of Single-Scattering Phase Function: “isotropic”, “Rayleigh”, or “HG1” (Henyey-Greenstein, one-sided)

hapkeModelType¶: Type of Hapke model: “IMSA” or “MIMSA”

n¶: Number of terms used for summation (if MIMSA option is used to compute P and/or M)

xi¶: Scattering parameter [0, 1]

xiFlat¶: Scattering parameter (converted to vector for matrix math)

Method Summary

MIMSAMultipleScattering(bn, cosi, cose)¶

Compute the MIMSA multiple-scattering component for the given SSPF type using n-term summation

Inputs:

obj (1x1 sonic.Hapke): object containing Hapke parameters
bn (nxm double):
cosi (nxm double): cosine of incidence angles
cose (nxm double): cosine of emission angles

Outputs:

P (nxm double): matrix of values for specified SSPF

References

[1] L. G. Henyey and J. L. Greenstein,: “Diffuse radiation in the Galaxy,” doi: 10.1086/144246.
[2] Lord Rayleigh (Strutt, J. W.), “X. On the: electromagnetic theory of light,” doi: 10.1080/14786448108627074

[3] J. A. Christian, “Spacecraft Optical Navigation”

Last revised: 10/4/2024 Last author: Jennifer Nolan

calcM(cosi, cose)¶

Compute the multiple-scattering component for the given SSPF type at the user-provided i, e, and g values

Inputs:

obj (1x1 sonic.Hapke): object containing Hapke parameters
cosi (nxm double): cosine of incidence angles
cose (nxm double): cosine of emission angles

Outputs:

P (nxm double): matrix of values for specified SSPF

References

[1] L. G. Henyey and J. L. Greenstein,: “Diffuse radiation in the Galaxy,” doi: 10.1086/144246.
[2] Lord Rayleigh (Strutt, J. W.), “X. On the: electromagnetic theory of light,” doi: 10.1080/14786448108627074

[3] J. A. Christian, “Spacecraft Optical Navigation”

Last revised: 10/4/2024 Last author: Jennifer Nolan

calcP(cosg)¶

P = calcSSPF(obj, p) Compute the selected single-scattering phase function for the given phase angle

Inputs:

obj (1x1 sonic.Hapke): object containing Hapke parameters
cosg (nxm double): cosine of phase angles (rad)

Outputs:

P (nxm double): matrix of values for specified SSPF

References

[1] L. G. Henyey and J. L. Greenstein,: “Diffuse radiation in the Galaxy,” doi: 10.1086/144246.
[2] Lord Rayleigh (Strutt, J. W.), “X. On the: electromagnetic theory of light,” doi: 10.1080/14786448108627074

[3] J. A. Christian, “Spacecraft Optical Navigation”

Last revised: 10/4/2024 Last author: Jennifer Nolan

refl(inputType, var1, var2, var3)¶

Creates object containing Hapke values

Inputs:

obj (1x1 sonic.Hapke): object containing Hapke parameters
inputType (1x1 string): defines subsequent set of inputs. Current supported inputs are:
- “iep” for incidence/emission/phase angles
- “iea” for incidence/emission/azimuth angles
- “ien” for incidence/emission/normal vectors
  – Must be column vectors, (3xn)
var1
var2
var3

Outputs:

r (:,:) (double): matrix of Hapke BRDF values

References

[1] J. A. Christian, “Spacecraft Optical Navigation”

Last revised: 10/4/2024 Last author: Jennifer Nolan