| Environments | PYTHON :: EASI :: MODELER |
| Batch Mode | Yes |
| Quick links | Description :: Parameters :: Parameter descriptions :: Details :: Acknowledgements :: References :: Related |
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| Name | Type | Length | Value range |
|---|---|---|---|
| Atmospheric Transformation | String | 0 - 1 | RADREF | REFRAD Default: RADREF |
| InputRLUT: Input radiance LUT input file name * | BIN port | 1 - | |
| InputCLUT: Input CLUT file name | BIN port | 0 - | |
| Input: Input file to be transformed * | Raster port | 1 - | |
| InputDEM | Integer | 0 - 1 | |
| InputAOD: Input aerosol optical depth map | Raster port | 0 - 1 | |
| InputSMR: Input surface meteorological range map | Raster port | 0 - 1 | |
| InputWVC: Input water-vapor content map | Raster port | 0 - 1 | |
| Output: Output transformed file name * | Raster port | 1 - | |
| Radiometric Transformation Level | Integer | 0 - 1 | |
| nominal Vertical Water Vapor Column | Float | 0 - 1 | |
| Nominal Aerosol Optical Depth | Float | 0 - 1 | |
| Nominal Surface Meteorological Range | Float | 0 - 1 | |
| Nominal Elevation | Float | 0 - 1 | |
| Adjacency Effect Window Dimension | Integer | 0 - 1 | Default: 1 |
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Atmospheric Transformation
Specifies the atmospheric transformation to apply.
InputRLUT: Input radiance LUT input file name
Specifies the name of the PCIDSK file that contains the radiance lookup table (RLUT).
InputCLUT: Input CLUT file name
Specifies the name of the PCIDSK file that contains the input spectral line curvature lookup table (CLUT).
Input: Input file to be transformed
Specifies the name of the input file that contains the data to be transformed.
InputDEM
Specifies the input channel that contains a DEM map of the scene to be transformed.
If this parameter is not specified, a nominal elevation (NOMELEV) is used over the entire scene. Only one channel can be specified.
InputAOD: Input aerosol optical depth map
Specifies the input channel that contains an aerosol optical depth map of the scene to be transformed.
If this parameter is not specified, a nominal aerosol optical depth (NOMAOD) is used over the entire scene. Only one channel can be specified.
The aerosol optical depth map (DBAOD) can be used as an alternative to the surface meteorological range map (DBSMR) in evaluating a surface meteorological range map. Only one these two parameters can be specified.
InputSMR: Input surface meteorological range map
Specifies the input channel that contains a surface meteorological range map of the scene to be transformed.
If this parameter is not specified, a nominal surface meteorological range (NOMSMR) is used over the entire scene. Only one channel can be specified.
The aerosol optical depth map (DBAOD) can be used as an alternative to the surface meteorological range map (DBSMR) in evaluating a surface meteorological range map. Only one these two parameters can be specified.
InputWVC: Input water-vapor content map
Specifies the input channel that contains an atmospheric water-vapor-content map of the scene to be transformed.
If this parameter is not specified, a nominal atmospheric water-vapor content (NOMVWVC) is used over the entire scene. Only one channel can be specified.
Output: Output transformed file name
Specifies the name of the output file to receive the transformed image data. The specified file must not exist prior to running ATRLUT.
Radiometric Transformation Level
Specifies the radiometric transformations already associated with the data set that is applied to the stored pixel values before any atmospheric transformation computations are performed. By default, the full sequence of transformations is applied.
This parameter has no effect if the data set metadata contains no radiometric transformation parameter values.
nominal Vertical Water Vapor Column
Specifies the nominal atmospheric water-vapor-content value (in g/cm^2) used over the entire scene. If the atmospheric water-vapor content setting was not specified in GENTP5 and GENRLUT when the RLUT was created, this parameter should be left unspecified.
If an input water-vapor content map (DBWVC) is specified, the nominal value is ignored.
Nominal Aerosol Optical Depth
Specifies the nominal aerosol-optical depth used over the entire scene. If either an input aerosol optical depth (DBAOD) or surface meteorological range (DBSMR) is specified, the nominal value is ignored.
If the meteorological range settings were not specified in GENTP5 and GENRLUT when the RLUT was created, this parameter should be left unspecified.
The nominal aerosol optical depth (NOMAOD) is used as an alternative to the surface meteorological range (NOMSMR) in evaluating a nominal surface meteorological range value. Only one of these two parameters can be specified.
Nominal Surface Meteorological Range
Specifies the nominal surface meteorological range value (in kilometers) used over the entire scene. If either an input aerosol optical depth (DBAOD) or surface meteorological range (DBSMR) is specified, the nominal value is ignored.
If the meteorological range settings were not specified in GENTP5 and GENRLUT when the RLUT was created, this parameter should be left unspecified.
The nominal aerosol optical depth (NOMAOD) is used as an alternative to the surface meteorological range (NOMSMR) in evaluating a nominal surface meteorological range value. Only one of these two parameters can be specified.
Nominal Elevation
Specifies the nominal elevation value (in meters, with respect to the WGS84 vertical datum) used for the entire scene. Either the nominal elevation (NOMELEV) or input scene elevation (DBDEM) must be specified. If an input scene (DBDEM) is specified, this parameter is ignored.
Adjacency Effect Window Dimension
Specifies the dimension of the neighborhood window used to compute adjacency radiance effects from heterogeneous terrain reflectance.
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ATRLUT performs automatic resampling of the input at-sensor radiance lookup table (RLUT) if the wavelength dimension sample does not match the data set band center wavelengths. Alternatively, you can use RESRLUT to resample the RLUT to match the response profile of the data set before running ATRLUT, which considerably reduces the ATRLUT execution time. The only exception is when an input spectral line curvature table is specified; in this case, the non-resampled RLUT should be used.
If a radiance-to-reflectance transformation is specified, the image data set at the specified radiometric transformation level and the RLUT must contain radiance values in the same units. Because the image data set band center wavelength values are always measured in nanometers, the radiance units must have a spectral component in nanometers.
If a reflectance-to-radiance transformation is specified, the image data set at the specified radiometric transformation level must contain reflectance values in fraction-of-one units (that is, in [0,1]). The computed radiance values are also in the same units as the RLUT radiance units. Because image data set band center wavelength values are always measured in nanometers, the radiance units must have a spectral component in nanometers.
ATRLUT reads elevation, aerosol-optical depth, surface meteorological range, and atmospheric water-vapor content from raster maps on a pixel-by-pixel basis. Atmospheric water-vapor content maps are generated using GENAWVC.
ATRLUT also allows the adjacency effect caused by non-homogeneous scenes to be taken into account by using the adjacency effect window dimension parameter.
If a CLUT is specified, the response profiles for each pixel are shifted according to the CLUT before performing the RLUT convolution and, subsequently, the atmospheric correction. When smile correction is desired, SLCCOR should follow ATRLUT, because each reflectance spectrum has its own response profile. See SLCCOR and GENCLUT for detailed information about smile correction and the suggested workflow.
If the selected atmospheric transformation is REFRAD, the generated data set is written to 32R channels with a single radiometric transformation with a gain of 1.0, an offset of 0.0, and a radiometric quantity of apparent radiance.
If the selected atmospheric transformation is RADREF, the generated data set is written to 16S channels with a single radiometric transformation with a gain of 0.0001, an offset of 0.0, and a radiometric quantity of surface reflectance.
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PCI Geomatics received financial support from the Canadian Space Agency/L'Agence Spatiale Canadienne through the Earth Observation Application Development Program (EOADP) for the development of this software, under contract 9F028-0-4902/12.
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Staenz, K. and D.J. Williams. "Retrieval of Surface Reflectance from Hyperspectral data: Using a Look-up Table Approach", Canadian Journal of Remote Sensing, 23 (1997): 354-368.
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