Isis 3 Application Documentation
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Perform photometric corrections on a cube
Description
Categories
Groups
Examples
History
1) Surface photometric function model type 2) Atmospheric photometric function model type 3) Type of normalization to be performedThe types of surface photometric function model types currently available in photomet are:
HapkeHen : Hapke-Henyey-Greenstein photometric model. Derive model albedo using complete Hapke model with Henyey-Greenstein single-particle phase function whose coefficients are Hg1 and Hg2, plus single scattering albedo Wh, opposition surge parameters Hh and B0, and macroscopic roughness Theta. Lambert : Simple photometric model which predicts that light incident on a surface is scattered uniformly in all directions; the total amount of reflected light depends on the incidence angle of the illumination. This function does not depend upon the outgoing light direction. LommelSeeliger : This model takes into account the radiance that results from single scattering (scattering of collimated incident light) and does not take into account the radiance that results from multiple scattering (scattering of diffuse light which has made its way indirectly to the same position by being scattered one or more times). This model depends on the incidence and emission angles. LunarLambert : This model combines a weighted sum of the LommelSeeliger and Lambert models. Given a suitable value for the LunarLambert function weight, L, this model fits the true reflectance behavior of many planetary surfaces equally well as the Hapke model. This model also depends on the incidence and emission angles. Minnaert : This model expands upon the Lambert function by introducing constant, K, that is used to describe the roughness of a surface. When the K constant is set to 1.0, then the Minnaert model is equivalent to the Lambert model. LunarLambertMcEwen : This model was developed specifically for use with the Moon. This model was designed to be used in conjunction with the MoonAlbedo normalization model.The types of atmospheric photometric function model types currently available in photomet are:
Anisotropic1 : Uses Chandrasekhar's solution for anisotropic scattering described by a one term Legendre polynomial. This model uses first order scattering approximation. Anisotropic2 : Uses Chandrasekhar's solution for anisotropic scattering described by a one term Legendre polynomial. This model uses second order scattering approximation. It is slower but more accurate than Anisotropic1. HapkeAtm1 : Provides an approximation for strongly anisotropic scattering that is similar to Hapke's model for a planetary surface. The Chandrasekhar solution for isotropic scattering is used for the multiple scattering terms, and a correction is made to the singly scattered light for anisotropic particle phase function. A one term Henyey Greenstein function is used. This model uses a first order scattering approximation. HapkeAtm2 : Provides an approximation for strongly anisotropic scattering that is similar to Hapke's model for a planetary surface. The Chandrasekhar solution for isotropic scattering is used for the multiple scattering terms, and a correction is made to the singly scattered light for anisotropic particle phase function. A one term Henyey Greenstein function is used. This model uses a second order scattering approximation. It is slower but more accurate than HapkeAtm1. Isotropic1 : Uses Chandrasekhar's solution for isotropic scattering. This model uses first order scattering approximation. Isotropic2 : Uses Chandrasekhar's solution for isotropic scattering. This model uses second order scattering approximation. It is slower but more accurate than Isotropic1.The types of normalization models currently available in photomet are:
Albedo : Normalization without atmosphere. Each pixel is divided by the model photometric function evaluated at the geometry of that pixel, then multiplied by the function at reference geometry with incidence and phase angles equal to Incref and emission angle 0. This has the effect of removing brightness variations due to incidence angle and showing relative albedo variations with the same contrast everywhere. If topographic shading is present, it will be amplified more in regions of low incidence angle and will not appear uniform. AlbedoAtm : Normalization with atmosphere. For each pixel, a model of atmospheric scattering is subtracted and a surface model is divided out, both evaluated at the actual geometry of the pixel. Then the resulting value is multiplied by the surface function at reference conditions is added. In normal usage, the reference condition has normal incidence (Incref=0) and no atmosphere (Tauref=0) but in some cases it may be desirable to normalize images to a different incidence angle or a finite optical depth to obtain a more uniform appearance. As with the Albedo model, if topographic shading is present, it will be amplified more at high incidence angles and will not appear uniform. Mixed : Normalization without atmosphere. Used to do albedo normalization over most of the planet, but near the terminator it will normalize topographic contrast to avoid the seams that can occur with the usual albedo normalization. The two effects will be joined seamlessly at incidence angle Incmat. Incmat must be adjusted to give the best equalization of contrast at all incidence angles. The Albedo parameter must also be adjusted so the topographically normalized regions at high incidence angle are set to an albedo compatible with the albedo-normalized data at lower incidence. MoonAlbedo : Normalization without atmosphere. This model was designed specifically for use on Lunar data. It will compute normalized albedo for the Moon, normalized to 0 degrees emission angle and 30 degrees illumination and phase angles. The LunarLambertMcEwen photometric function was designed to be used with this normalization model. NoNormalization : Normalization without atmosphere. No normalization is performed. Only photometric correction is performed. Shade : Normalization without atmosphere. The surface photometric function is evaluated at the geometry of the image in order to calculate a shaded relief image of the ellipsoid (and in the future the DEM). The radiance of the model surface is set to Albedo at incidence angle Incref and zero phase. The image data is not used. ShadeAtm : Normalization with atmosphere. The surface photometric function is used to simulate an image by relief shading, just like the Shade model, but the effects of atmospheric scattering are also included in the calculation. Topo : Normalization without atmosphere. Used to normalize topographic shading to uniform contrast regardless of incidence angle. Such a normalization would exagerate albedo variations at large incidence angles, so this model is used as part of a three step process in which (1) the image is temporarily normalized for albedo; (2) a highpass divide filter is used to remove regional albedo variations; and (3) the image is renormalized with the Topo mode to undo the first normalization and equalize topographic shading. The reference state in the first step MUST have Incref=0 because this is waht is undone in the final step. If there are no significant albedo variations, step (2) can be skipped but step (1) must not be. TopoAtm : Normalization with atmosphere. As with the Topo model, this option is used in the final step of a three step process: (1) normalize with the AlbedoAtm model, Incref=0, and Tauref=0 to temporarily remove atmosphere and normalize albedo variations; (2) use highpass divide filter to remove albedo variations; and (3) normalize with the TopoAtm model to undo the temporary normalization and equalize topographic shading.As you can see above, the only normalization models that make use of atmospheric correction are: AlbedoAtm, ShadeAtm, and TopoAtm. Atmospheric correction is not applied by any of the other normalization models. If you specify an atmospheric model in a PVL along with a normalization model that does not do atmospheric correction, then the atmospheric model will be ignored. Each of the above photometric, atmospheric, and normalization models has specific parameters that apply to them. Here is a list of the models and their related parameters (in parentheses):
HapkeHen (B0,Hg1,Hg2,Hh,Theta,Wh) Lambert LommelSeeliger LunarLambert (L) Minnaert (K) LunarLambertMcEwen Anisotropic1 (Bha,Bharef,Hnorm,Nulneg,Tau,Tauref,Wha,Wharef) Anisotropic2 (Bha,Bharef,Hnorm,Nulneg,Tau,Tauref,Wha,Wharef) HapkeAtm1 (Hga,Hgaref,Hnorm,Nulneg,Tau,Tauref,Wha,Wharef) HapkeAtm2 (Hga,Hgaref,Hnorm,Nulneg,Tau,Tauref,Wha,Wharef) Isotropic1 (Hnorm,Nulneg,Tau,Tauref,Wha,Wharef) Isotropic2 (Hnorm,Nulneg,Tau,Tauref,Wha,Wharef) Albedo (Albedo,Incmat,Incref,Thresh) AlbedoAtm (Incref) Mixed (Albedo,Incmat,Incref,Thresh) MoonAlbedo (Bsh1,D,E,F,G2,H,Wl,Xb1,Xb2,Xmul) NoNormalization Shade (Albedo,Incref) ShadeAtm (Albedo,Incref) Topo (Albedo,Incref,Thresh) TopoAtm (Albedo,Incref)Here is a description of each parameter along with a valid range of values and the default for that parameter:
Photometric parameters: ----------------------- B0: Hapke opposition surge component: 0 <= value : default is 0.0 Bh: Hapke Legendre coefficient for single particle phase function: -1 <= value <= 1 : default is 0.0 Ch: Hapke Legendre coefficient for single particle phase function: -1 <= value <= 1 : default is 0.0 Hg1: Hapke Henyey Greenstein coefficient for single particle phase function: -1 < value < 1 : default is 0.0 Hg2: Hapke Henyey Greenstein coefficient for single particle phase function: 0 <= value <= 1 : default is 0.0 Hh: Hapke opposition surge component: 0 <= value : default is 0.0 K: Minnaert function exponent: 0 <= value : default is 1.0 L: Lunar-Lambert function weight: no limit : default is 1.0 Theta: Hapke macroscopic roughness component: 0 <= value <= 90 : default is 0.0 Wh: Hapke single scattering albedo component: 0 < value <= 1 : default is 0.5 Atmospheric parameters: ----------------------- Bha : Coefficient of the single particle Legendre phase function: -1 <= value <= 1 : default is 0.85 Hga : Coefficient of single particle Henyey Greenstein phase function: -1 < value < 1 : default is 0.68 Hnorm : Atmospheric shell thickness normalized to the planet radius: 0 <= value : default is .003 Nulneg : Determines if negative values after removal of atmospheric effects will be set to NULL: YES or NO : default is NO Tau : Normal optical depth of the atmosphere: 0 <= value : default is 0.28 Tauref : Reference value of Tau to which the image will be normalized: 0 <= value : default is 0.0 Wha : Single scattering albedo of atmospheric particles: 0 < value < 1 : default is 0.95 Normalization parameters: ------------------------- Albedo : Albedo to which the image will be normalized: no limit : default is 1.0 Bsh1 : Albedo dependent phase function normalization parameter: 0 <= value : default is 0.08 D : Albedo dependent phase function normalization parameter: no limit : default is 0.14 E : Albedo dependent phase function normalization parameter: no limit : default is -0.4179 F : Albedo dependent phase function normalization parameter: no limit : default is 0.55 G2 : Albedo dependent phase function normalization parameter: no limit : default is 0.02 H : Albedo dependent phase function normalization parameter: no limit : default is 0.048 Incmat : Specifies incidence angle where albedo normalization transitions to incidence normalization: 0 <= value < 90 : default is 0.0 Incref : Reference incidence angle to which the image will be normalized: 0 <= value < 90 : default is 0.0 Thresh : Sets upper limit on amount of amplification in regions of small incidence angle: no limit : default is 30.0 Wl : Wavelength in micrometers of the image being normalized: no limit : default is 1.0 Xb1 : Albedo dependent phase function normalization parameter: no limit : default is -0.0817 Xb2 : Albedo dependent phase function normalization parameter: no limit : default is 0.0081 Xmul : Used to convert radiance to reflectance or apply a calibration fudge factor: no limit : default is 1.0Here are some example PVL files:
Example 1: Object = PhotometricModel Group = Algorithm Name = Lambert EndGroup EndObject Object = NormalizationModel Group = Algorithm Name = NoNormalization EndGroup EndObject -------------------------------- Example 2: Object = PhotometricModel Group = Algorithm Name = Minnaert K = .5 EndGroup EndObject Object = NormalizationModel Group = Algorithm Name = Albedo Incref = 0.0 Incmat = 0.0 Albedo = 1.0 Thresh = 30.0 EndGroup EndObject -------------------------------- Example 3: Object = PhotometricModel Group = Algorithm Name = HapkeHen Wh = 0.52 Hh = 0.0 B0 = 0.0 Theta = 30.0 Hg1 = .213 Hg2 = 1.0 EndGroup EndObject Object = AtmosphericModel Group = Algorithm Name = HapkeAtm2 Hnorm = .003 Tau = 0.28 Tauref = 0.0 Wha = .95 Hga = 0.68 EndGroup EndObject Object = NormalizationModel Group = Algorithm Name = AlbedoAtm Incref = 0.0 EndGroup EndObject -------------------------------- Example 4 (Used to process Clementine UVVIS filter "a" data): Object = PhotometricModel Group = Algorithm Name = LunarLambertMcEwen EndGroup EndObject Object = NormalizationModel Group = Algorithm Name = MoonAlbedo D = 0.0 E = -0.222 F = 0.5 G2 = 0.39 H = 0.062 Bsh1 = 2.31 EndGroup EndObject -------------------------------- Example 5 (Used to process Clementine UVVIS filter "b" data): Object = PhotometricModel Group = Algorithm Name = LunarLambertMcEwen EndGroup EndObject Object = NormalizationModel Group = Algorithm Name = MoonAlbedo D = 0.0 E = -0.218 F = 0.5 G2 = 0.4 H = 0.054 Bsh1 = 1.6 EndGroup EndObject -------------------------------- Example 6 (Used to process Clementine UVVIS filter "cde" data): Object = PhotometricModel Group = Algorithm Name = LunarLambertMcEwen EndGroup EndObject Object = NormalizationModel Group = Algorithm Name = MoonAlbedo D = 0.0 E = -0.226 F = 0.5 G2 = 0.36 H = 0.052 Bsh1 = 1.35 EndGroup EndObject
Name | Description |
---|---|
FROM | Input cube |
TO | Output cube |
FROMPVL | Pvl file |
Name | Description |
---|---|
MAXEMISSION | Maximum emisson angle |
MAXINCIDENCE | Maximum incidence angle |
USEDEM | Use DEM photometric angles when trimming |
Name | Description |
---|---|
ANGLESOURCE | Source of photometric angles: ELLIPSOID, DEM, or CENTER |
PHASE_ANGLE | Center phase angle |
INCIDENCE_ANGLE | Center incidence angle |
EMISSION_ANGLE | Center emission angle |
Name | Description |
---|---|
PHTNAME | Photometric model to be used |
THETA | Macroscopic Roughness Angle |
WH | Single Scattering Albedo |
HG1 | Hapke Henyey Greenstein Coefficient |
HG2 | Hapke Henyey Greenstein Coefficient |
BH | Hapke Legendre Coefficient |
CH | Hapke Legendre Coefficient |
HH | Hapke Opposition Surge |
B0 | Hapke Opposition Surge |
ZEROB0STANDARD | Determines if opposition surge (B0) is set to zero when standard conditions are used |
L | Lunar-Lambert Function Weight |
K | Minnaert Function Exponent |
PHASELIST | Minnaert Empirical Function Phase Angle List |
KLIST | Minnaert Empirical Function Limb Darkening Parameter List |
LLIST | Lunar Lambert Empirical Function Limb Darkening Parameter List |
PHASECURVELIST | Minnaert Empirical Function Phase Curve Value List |
Name | Description |
---|---|
ATMNAME | Atmospheric model to be used |
NULNEG | Determines if negative values will be set to NULL |
TAU | Optical Depth of Atmosphere |
TAUREF | Reference Value of Tau |
HGA | Henyey Greenstein Coefficient |
WHA | Single Scattering Albedo |
BHA | Legendre Coefficient |
HNORM | Atmospheric Shell Thickness |
Name | Description |
---|---|
NORMNAME | Normalization model to be used |
INCREF | Reference Incidence Angle |
INCMAT | Incidence Angle |
THRESH | Amplification Threshold |
ALBEDO | Albedo |
D | Albedo Normalization Parameter |
E | Albedo Normalization Parameter |
F | Albedo Normalization Parameter |
G2 | Albedo Normalization Parameter |
H | Albedo Normalization Parameter |
XMUL | Radiance to Reflectance/Calibration Factor |
WL | Wavelength |
BSH1 | Albedo Normalization Parameter |
XB1 | Albedo Normalization Parameter |
XB2 | Albedo Normalization Parameter |
Use this parameter to select the input filename.
Type | cube |
---|---|
File Mode | input |
Filter | *.cub |
This file will contain the of the photometric correction.
Type | cube |
---|---|
File Mode | output |
Pixel Type | real |
This file will contain the photometric parameters to use when doing the photometric correction.
Type | filename |
---|---|
File Mode | input |
Default Path | $base/templates/photometry |
Internal Default | None Specified |
Filter | *.pvl |
The maximum number of degrees allowed for the emission angle. This number must be between 0.0 and 90.0.
Type | double |
---|---|
Default | 90.0 |
Minimum | 0.0 (inclusive) |
Maximum | 90.0 (inclusive) |
The maximum number of degrees allowed for the incidence angle. This number must be between 0.0 and 90.0.
Type | double |
---|---|
Default | 90.0 |
Minimum | 0.0 (inclusive) |
Maximum | 90.0 (inclusive) |
This determines if the trimming will be performed based on the photometric angles obtained from the DEM surface. If this parameter is set to False, then the photometric angles will be obtained from the ellipsoidal surface.
Type | boolean |
---|---|
Default | FALSE |
Phase, Incidence, and Emission angles can be calculated from the ellipsoid (default), from the DEM, or from the center of the image. When using the DEM, the surface roughness is taken into account to calculate a surface normal which is used to calculate the photometric angles. When the center of the image is used, then the photometric angles are determined at the center pixel of the FROM image based on the ellipsoid and every pixel in the image is photometrically corrected using that same set of photometric angles.
Type | combo | ||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Default | ELLIPSOID | ||||||||||||||||||
Internal Default | ELLIPSOID | ||||||||||||||||||
Option List: |
|
The center phase angle to use if the CENTER_FROM_USER option is chosen.
Type | double |
---|---|
Default | 0.0 |
Minimum | 0.0 (inclusive) |
Maximum | 180.0 (inclusive) |
The center incidence angle to use if the CENTER_FROM_USER option is chosen.
Type | double |
---|---|
Default | 0.0 |
Minimum | 0.0 (inclusive) |
Maximum | 90.0 (inclusive) |
The center emission angle to use if the CENTER_FROM_USER option is chosen.
Type | double |
---|---|
Default | 0.0 |
Minimum | 0.0 (inclusive) |
Maximum | 90.0 (inclusive) |
This is the name of the surface photometric function model
Type | combo | |||||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Default | NONE | |||||||||||||||||||||||||||||||||
Internal Default | NONE | |||||||||||||||||||||||||||||||||
Option List: |
|
The Hapke macroscopic roughness component.
Type | string |
---|---|
Default | None Specified |
Internal Default | None Specified |
Minimum | 0.0 (inclusive) |
Maximum | 90.0 (inclusive) |
The Hapke single scattering albedo component.
Type | string |
---|---|
Default | None Specified |
Internal Default | None Specified |
Minimum | 0.0 (exclusive) |
Maximum | 1.0 (inclusive) |
The Hapke Henyey Greenstein coefficient for single particle phase function.
Type | string |
---|---|
Default | None Specified |
Internal Default | None Specified |
Minimum | -1.0 (exclusive) |
Maximum | 1.0 (exclusive) |
The Hapke Henyey Greenstein coefficient for single particle phase function.
Type | string |
---|---|
Default | None Specified |
Internal Default | None Specified |
Minimum | 0.0 (inclusive) |
Maximum | 1.0 (inclusive) |
The Hapke Legendre coefficient for single particle phase function.
Type | string |
---|---|
Default | None Specified |
Internal Default | None Specified |
Minimum | -1.0 (exclusive) |
Maximum | 1.0 (exclusive) |
The Hapke Legendre coefficient for single particle phase function.
Type | string |
---|---|
Default | None Specified |
Internal Default | None Specified |
Minimum | -1.0 (exclusive) |
Maximum | 1.0 (exclusive) |
The Hapke opposition surge component.
Type | string |
---|---|
Default | None Specified |
Internal Default | None Specified |
Minimum | 0.0 (inclusive) |
The Hapke opposition surge component.
Type | string |
---|---|
Default | None Specified |
Internal Default | None Specified |
Minimum | 0.0 (inclusive) |
This determines if the opposition surge component B0 is set to zero during the standard conditions phase.
Type | string | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
Default | TRUE | |||||||||
Option List: |
|
The Lunar-Lambert function weight.
Type | string |
---|---|
Default | None Specified |
Internal Default | None Specified |
The Minnaert function exponent.
Type | string |
---|---|
Default | None Specified |
Internal Default | None Specified |
Minimum | 0.0 (inclusive) |
The Minnaert empirical function phase angle list.
Type | string |
---|---|
Default | No List |
Internal Default | No List |
The Minnaert empirical function exponent list.
Type | string |
---|---|
Default | No List |
Internal Default | No List |
The Lunar Lambert empirical function exponent list.
Type | string |
---|---|
Default | No List |
Internal Default | No List |
The Minnaert empirical function phase curve value list.
Type | string |
---|---|
Default | No List |
Internal Default | No List |
This is the name of the atmospheric photometric function model. This can only be used with the three atmospheric normalization models: AlbedoAtm, ShadeAtm, and TopoAtm.
Type | combo | ||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Default | NONE | ||||||||||||||||||||||||
Internal Default | NONE | ||||||||||||||||||||||||
Option List: |
|
This determines if negative values after removal of atmospheric effects will be set to NULL.
Type | string | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Default | READFROMPVL | ||||||||||||
Option List: |
|
The normal optical depth of the atmosphere.
Type | string |
---|---|
Default | None Specified |
Internal Default | None Specified |
Minimum | 0.0 (inclusive) |
The reference value of Tau to which the image will be normalized.
Type | string |
---|---|
Default | None Specified |
Internal Default | None Specified |
Minimum | 0.0 (inclusive) |
The coefficient of single particle Henyey Greenstein phase function.
Type | string |
---|---|
Default | None Specified |
Internal Default | None Specified |
Minimum | -1.0 (exclusive) |
Maximum | 1.0 (exclusive) |
The single scattering albedo of atmospheric particles.
Type | string |
---|---|
Default | None Specified |
Internal Default | None Specified |
Minimum | 0.0 (exclusive) |
Maximum | 1.0 (inclusive) |
The coefficient of the single particle Legendre phase function.
Type | string |
---|---|
Default | None Specified |
Internal Default | None Specified |
Minimum | -1.0 (inclusive) |
Maximum | 1.0 (inclusive) |
The atmospheric shell thickness normalized to the planet radius.
Type | string |
---|---|
Default | None Specified |
Internal Default | None Specified |
Minimum | 0.0 (inclusive) |
This is the name of the normalization model to be performed
Type | combo | ||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Default | NONE | ||||||||||||||||||||||||||||||
Internal Default | NONE | ||||||||||||||||||||||||||||||
Option List: |
|
The reference incidence angle to which the image will be normalized.
Type | string |
---|---|
Default | None Specified |
Internal Default | None Specified |
Minimum | 0.0 (inclusive) |
Maximum | 90.0 (exclusive) |
This specifies the incidence angle where albedo normalization transition to incidence normalization.
Type | string |
---|---|
Default | None Specified |
Internal Default | None Specified |
Minimum | 0.0 (inclusive) |
Maximum | 90.0 (exclusive) |
This sets upper limit on amount of amplification in regions of small incidence angle.
Type | string |
---|---|
Default | None Specified |
Internal Default | None Specified |
The albedo to which the image will be normalized.
Type | string |
---|---|
Default | None Specified |
Internal Default | None Specified |
The albedo dependent phase function normalization parameter.
Type | string |
---|---|
Default | None Specified |
Internal Default | None Specified |
The albedo dependent phase function normalization parameter.
Type | string |
---|---|
Default | None Specified |
Internal Default | None Specified |
The albedo dependent phase function normalization parameter.
Type | string |
---|---|
Default | None Specified |
Internal Default | None Specified |
The albedo dependent phase function normalization parameter.
Type | string |
---|---|
Default | None Specified |
Internal Default | None Specified |
The albedo dependent phase function normalization parameter.
Type | string |
---|---|
Default | None Specified |
Internal Default | None Specified |
This is used to convert radiance to reflectance or apply a calibration factor.
Type | string |
---|---|
Default | None Specified |
Internal Default | None Specified |
The wavelength in micrometers of the image being normalized.
Type | string |
---|---|
Default | None Specified |
Internal Default | None Specified |
The albedo dependent phase function normalization parameter.
Type | string |
---|---|
Default | None Specified |
Internal Default | None Specified |
The albedo dependent phase function normalization parameter.
Type | string |
---|---|
Default | None Specified |
Internal Default | None Specified |
The albedo dependent phase function normalization parameter.
Type | string |
---|---|
Default | None Specified |
Internal Default | None Specified |
Photometric corrections with any valid angles
Example GUI Screenshot of GUI version of the application. Notice the default values of 90.0 are left alone for the MAXEMISSION and MAXINCIDENCE parameters. |
Example input cube
Parameter Name:
FROM
Screenshot of the input image before photometric correction has been performed. |
Example input PVL | Pvl file including the input photometric parameters for the input cube. |
---|
Example output cube
Parameter Name:
TO
Screenshot of the output image after photometric correction. Notice many features on the surface are easier to view due to the normalization of the pixels. |
Photometric corrections using maximum emission angle parameter
Example GUI Screenshot of GUI version of the application. Notice the MAXEMISSION parameter is changed from the default value of 90.0. |
Example input cube
Parameter Name:
FROM
Screenshot of the input image before photometric correction has been performed. |
Example input PVL | Pvl file including the input photometric parameters for the input cube. |
---|
Example output cube
Parameter Name:
TO
Screenshot of the output image after photometric correction. Notice there are more blackened areas than in the Example 1 output image. This happens since the pixel values have been set to null where the emission angles are greater than 75. |
Photometric corrections using maximum incidence angle parameter
Example GUI Screenshot of GUI version of the application. Notice the MAXINCIDENCE parameter is changed from the default value of 90.0. |
Example input cube
Parameter Name:
FROM
Screenshot of the input image before photometric correction has been performed. |
Example input PVL | Pvl file including the input photometric parameters for the input cube. |
---|
Example output cube
Parameter Name:
TO
Screenshot of the output image after photometric correction. Notice there are different areas of valid pixels from Examples 1 and 2 output images. This happens since the pixel values have been set to null where the incidence angles are greater than 85, but the emission angle parameter is kept at default. |
Photometric corrections using maximum emission and incidence angle parameters
Example GUI Screenshot of GUI version of the application. Notice the MAXEMISSION and MAXINCIDENCE parameters are changed from the default values of 90.0. |
Example input cube
Parameter Name:
FROM
Screenshot of the input image before photometric correction has been performed. |
Example input PVL | Pvl file including the input photometric parameters for the input cube. |
---|
Example output cube
Parameter Name:
TO
Screenshot of the output image after photometric correction. Notice this output image contains the overlapping valid pixels from Examples 2 and 3. |
Tammy Becker | 1989-02-15 | Original version - based on Tammy Becker's photom/photompr programs which were later converted to Randy Kirk's photomet |
Janet Barrett | 2008-03-07 | Added code to acquire the BandBin Center keyword from the input image. This value is needed in case the user chooses the MoonAlbedo normalization method. |
Steven Lambright | 2008-05-13 | Removed references to CubeInfo |
Jeannie Walldren | 2009-01-08 | Added MAXEMISSION and MAXINCIDENCE parameters. Modified code to set off-target pixels to NULL. Added appTests for new parameters. Added user documentation examples. |
Eric Hyer | 2010-11-10 | Added USEDEM parameter. |
Janet Barrett | 2010-11-22 | Added error check for situations where there is not an intersection with the DEM and the local photometric angles are requested. |
Janet Barrett | 2010-11-23 | Added capability to use both ellipsoid and DEM photometric angles in atmospheric corrections. This provides the ability to do shading using a DEM surface. |
Janet Barrett | 2011-02-22 | The USEDEM parameter has been removed and the ANGLESOURCE parameter has been added. The ANGLESOURCE parameter lets you specify the source where the photometric angles will come from: ellipsoid, DEM, or center of image. |
Janet Barrett | 2011-03-29 | The CENTER option of the ANGLESOURCE parameter has been removed and the CENTER_FROM_IMAGE, CENTER_FROM_LABEL and CENTER_FROM_USER options have been added. This allows the user to determine where the center photometric angles will come from. |
Janet Barrett | 2011-09-23 | The following changes were made to the program for the ISIS3.3.0 release: 1) The PHOPAR parameter name was changed to FROMPVL - this was done to have consistent parameter names throughout the photometry software. 2) All radio button options are now accessed through drop down menus. The only radio button options that existed prior to this release were those for choosing the ANGLESOURCE. In order to use any of the drop down menus, click on the drop down menu and hold the mouse button down while navigating to the choice that you want. 3) Added a USEDEM option which will let you determine how the trim is performed. If you don't check the USEDEM box, then trimming is performed based on the photometric angles of the ellipsoid. If you check the USEDEM box, then the trimming is performed based on the photometric angles of the DEM (if one is specified in the image labels). If there is no DEM associated with your FROM file, then the default is to use the ellipsoid. 4) The program now lets you specify the photometric model, atmospheric model, and normalization model through the PHTNAME, ATMNAME, and NORMNAME drop down menus. Prior to this release, you were forced to provide an input PVL file with all of the model information in it. You can now provide the model information through the PVL, the GUI, or a combination of both. If you provide a FROMPVL file, then you need to use the GUI to specify which model(s) to use from that file. If you change any of the model-specific parameters in the GUI, then they will override the values in the FROMPVL file. 5) The BHAREF, HGAREF, and WHAREF parameters have been removed because they were obsolete. 6) The NONORMALIZATION model was removed because it duplicated the functionality of the SHADE model. 7) More photometric models have been added. The Hapke Legendre, Minnaert Empirical, and Lunar Lambert Empirical models have been added. The Minnaert Empirical model has parameters PHASELIST, PHASECURVELIST, and KLIST associated with it. The information for the new parameters is a list of comma delimited values (phase angle goes in PHASELIST, brightness values go in PHASECURVELIST, and limb darkening values go in KLIST). The Lunar Lambert Empirical model has parameters PHASELIST, PHASECURVELIST, and LLIST where LLIST is similar to the KLIST parameter for Minnaert Empirical. 8) A USEDEM parameter has been added which allows the user to determine which photometric angles to use for trimming. If the USEDEM parameter is set to false, then the photometric angles of the ellipsoid are used. If USEDEM is set to true, then the photometric angles of the DEM shape model are used for trimming. 9) Helper buttons were added to the FROMPVL to allow you to View a PVL or to Load a PVL. PLEASE NOTE: When loading a Minnaert Empirical or Lunar Lambert Empirical model from a PVL, only the first value will be loaded into the GUI. This is a known problem and will be fixed in the next patch or release to ISIS. 10) ***NOTE*** The Minnaert Empirical and Lunar Lambert Empirical models do not load properly from a PVL file when using the Load Pvl helper button. This is a known problem and will be fixed in the next patch or release of ISIS. |
Janet Barrett | 2011-11-04 | The ZEROB0STANDARD parameter for the Hapke models was not added to the new update of photomet during the last release. This parameter is responsible for determining if the Hapke opposition surge component B0 is set to zero when calculations are based on standard conditions. This parameter has been added to the new interface to photomet. |
Janet Barrett | 2012-01-10 | The program was fixed to make it backwards compatible with older PVL files. If you tried running this program with an older PVL, then you most likely got the following error message "A Normalization model must be specified before running this program.". This message would have occurred even if you had a Normalization model specified in your FROMPVL file. This problem has been fixed. If your FROMPVL file specifies a Normalization model, then you aren't required to specify one through the program interface as well. |