RLUTSP

Description

Extracts radiance spectra from a radiance lookup table (RLUT) according to user-specified table dimension intervals and outputs them to a file. The user also specifies whether to extract spectra for LG, the at-sensor radiance reflected by the target, or LO, the at-sensor radiance from all other sources.

Parameters

Name	Type	Length	Value range
Input: Input at-sensor radiance LUT segment *	BIN port	1 - 1
Output Spectral Library *	String	1 -
Spectral Library File Format	String	0 -	SPCB|XLS|TXT Default: SPCB
Radiance Spectrum Type	String	0 - 1	LG | LO Default: LG
Reflectance Interval *	Float	2 - 2	1.0,1.0
Relative View-Solar Azimuth Interval *	Float	2 - 2	360.0,360.0
View Zenith Angle Interval *	Float	2 - 2	180.0,180.0
Solar Zenith Angle Interval *	Float	2 - 2	90.0,90.0
Vertical Water Vapor Content Interval	Float	0 - 2	Default: 0.0,0.0
Aerosol Optical Depth Range Interval	Float	0 - 2	2.0,2.0
Surface Meteorological Range Interval	Float	0 - 2
Scene Elevation Interval *	Float	2 - 2
Sensor Altitude Interval *	Float	2 - 2

* Required parameter

Parameter descriptions

Input: Input at-sensor radiance LUT segment

Specifies the input segment that contains the radiance LUT.

Output Spectral Library

Specifies the name of the output spectral library file.

Spectral Library File Format

Specifies the file format for the output spectral library file.

Radiance Spectrum Type

Specifies the type of radiance spectra to be extracted.

Reflectance Interval

Specifies, in percentage, the reflectance interval endpoints.

An endpoint value e must be such that 0 < e <= 1.

Relative View-Solar Azimuth Interval

Specifies, in degrees, the relative view-solar azimuth (solar azimuth minus view azimuth) interval endpoints.

An endpoint value e must be such that -360 <= e <= 360.

View Zenith Angle Interval

Specifies, in degrees, the view zenith angle interval endpoints.

An endpoint value e must be such that 90 <= e <= 180.

Solar Zenith Angle Interval

Specifies, in degrees, the solar zenith angle interval endpoints.

An endpoint value e must be such that 0 <= e <= 90.

Vertical Water Vapor Content Interval

Specifies, in g/cm^2, the atmospheric water vapor content interval endpoints.

An endpoint value e must be such that e >= 0. If the input radiance LUT was created by specifying a default atmospheric water vapor content interval, this parameter should be left unspecified.

Aerosol Optical Depth Range Interval

Specifies the aerosol optical depth interval endpoints (at 550nm).

An endpoint value e must be such that 0 <= e <= 2.

The aerosol optical depth range interval (AODINT) can be used as an alternative to the surface meteorological range interval (SMRINT) to evaluate the surface meteorological range map. Only one these two parameters can be specified.

If the input radiance LUT was created by specifying a default surface meteorological range interval, this parameter should be left unspecified.

Surface Meteorological Range Interval

Specifies, in km, the surface meteorological range interval endpoints.

An endpoint value e must be such that 0 < e.

The aerosol optical depth range interval (AODINT) can be used as an alternative to the surface meteorological range interval (SMRINT) to evaluate the surface meteorological range map. Only one these two parameters can be specified.

If the input radiance LUT was created by specifying a default surface meteorological range interval, this parameter should be left unspecified.

Scene Elevation Interval

Specifies the scene elevation interval endpoints, in meters with respect to the WGS84 vertical datum.

Sensor Altitude Interval

Specifies the sensor altitude interval endpoints, in meters with respect to the WGS84 vertical datum.

Details

RLUTSP is designed to be used in combination with GENRLUT and RESRLUT. It extracts radiance spectra from an input radiance lookup table (RLUT) according to user-specified table dimension intervals and outputs them to a file. Only the specified radiance spectra type is extracted. The input RLUT must conform to the RLUT format requirements and contain all mandatory metadata tags.

The function outputs only the spectra that match the specified coordinate interval criteria.

Each output spectrum will have unique name depending on its RLUT index. For example, the spectrum corresponding to multidimensional array index {0,1,2,3,4,5,6,7} will be named 0_1_2_3_4_5_6_7_LG or 0_1_2_3_4_5_6_7_LO, depending on the spectrum component chosen.

The report will list the total number of spectra extracted.

Because the RLUT binary format does not allow data inspection, RLUTSP is the only tool available for RLUT data extraction and validation.

References

Staenz, K., and Williams D.J., 1997. "Retrieval of Surface Reflectance from Hyperspectral Data Using a Lookup Table Approach," Canadian Journal of Remote Sensing, Vol. 23, No. 4, pp. 354-368.