Hapke Model April 2019

Input Files

Data files containing a single matrix each. Either Matlab (.mat) format or ASCII text format is accepted. Wavelength units should be either nm or microns (not wavenumbers).

VNIR spectrum - 1 VNIR spectrum - 2 VNIR spectrum - 3

Add More Calibration wavelength Calibration spectrum

Known variables

Incident angle (θ_i), in degrees.

Emission angle (θ_e), in degrees.

Average n, usually at the sodium D line.

Opposition surge (B_g), can be zero if |θ_i - θ_e| > 15.

Modeling choices

Phase function

Scattering model

Use Hu Approximation:

Bounds

Usable range of wavelengths (in microns). Use the plots above to determine good cutoffs.

Lower bound of good region.

Upper bound of good region.

Lower bound after extrapolating the cropped spectrum.

Interpolation options

Polynomial order.

Initial Points to Fit

Note: The bounds for Henyey Greenstein Function - 0 <= b <= 1, 0 <= c <= 1.
The bounds for Legendre Function - -1.7 <= b <= 1.7, -1 <= c <= 2

Optimization Parameters

Previous section to take the initial guess for k from.

Lower/upper bounds for each value in k.

Minimization Parameters

Max Function Evaluations D1:

Function Tolerance (smaller is closer match):

X Tolerance:

Start Points:

Diff step:

Matlab MAT-files containing a single matrix each. Wavelength units should be either nm or microns (not wavenumbers).

MIR wavelength (v) MIR dispersion (k) Repeat (k) [Minimized from the last section]

Adjustment Type:

If you don't have MIR data, in Adjustment Type - use option No MIR data

Known variables

Anchor wavelength, at which the average n (above) was determined.

Phase Files

Phase Angle Count: Add Phase Angles

Parameters Affecting k

Min Scale:

Max Scale:

Min Offset:

Max Offset:

Minimization Parameters

Max Function Evaluations D1:

Function Tolerance (smaller is closer match):

X Tolerance:

Start Points:

Fit Order:

Diff step:

Note: The bounds for Henyey Greenstein Function - 0 <= b <= 1, 0 <= c <= 1.
The bounds for Legendre Function - -1.7 <= b <= 1.7, -1 <= c <= 2

Optimization Parameters

Lower/upper bounds for each value in k.

Minimization Parameters

Max Function Evaluations D1:

Function Tolerance (smaller is closer match):

X Tolerance:

Start Points:

Diff step: