SPECL

Description

SPECL creates a spectral classification from ground-reflectance data. The algorithm is a spectral-rule classification that creates a quality layer for use with atmospheric-correction (ATCOR) products. You can also use the quality layer for mosaicking or otherwise creating composite images. For a list of supported sensors, see Supported sensors.

Parameters

Name	Type	Length	Value range
Input1: Atmospherically corrected blue band (0.4\u00e2\u20ac\u201c0.52 microns)*	Raster port	1 - 1
Input2: Atmospherically corrected green band (0.52\u00e2\u20ac\u201c0.6 microns)*	Raster port	1 - 1
Input3: Atmospherically corrected red band (0.62\u00e2\u20ac\u201c0.71 microns)*	Raster port	1 - 1
Input4: Atmospherically corrected NIR band (0.78\u00e2\u20ac\u201c0.89 microns)*	Raster port	1 - 1
Input5: Atmospherically corrected SWIR band (1.5\u00e2\u20ac\u201c1.8 microns)*	Raster port	1 - 1
Input6: Atmospherically corrected SWIR1 band (2.1\u00e2\u20ac\u201c2.35 microns)	Raster port	0 - 1
Output	String	0 -
OutputPCT	String	0 -
Source background options	String	0 -	Default: File metadata
Source background values	Integer	0 - 1024	Default: 0

* Required parameter

Parameter descriptions

Input1: Atmospherically corrected blue band (0.4\u00e2\u20ac\u201c0.52 microns)

The image channel in the input file that contains the blue band (0.4\u00e2\u20ac\u201c0.52 microns).

Input2: Atmospherically corrected green band (0.52\u00e2\u20ac\u201c0.6 microns)

The image channel in the input file that contains the green band (0.52\u00e2\u20ac\u201c0.6 microns).

Input3: Atmospherically corrected red band (0.62\u00e2\u20ac\u201c0.71 microns)

The image channel in the input file that contains the red band (0.62\u00e2\u20ac\u201c0.71 microns).

Input4: Atmospherically corrected NIR band (0.78\u00e2\u20ac\u201c0.89 microns)

The image channel in the input file that contains the near-infrared (NIR) band (0.78\u00e2\u20ac\u201c0.89 microns).

Input5: Atmospherically corrected SWIR band (1.5\u00e2\u20ac\u201c1.8 microns)

The image channel in the input file that contains the shortwave-infrared (SWIR) band (1.5\u00e2\u20ac\u201c1.8 microns).

Input6: Atmospherically corrected SWIR1 band (2.1\u00e2\u20ac\u201c2.35 microns)

The image channel in the input file that contains the shortwave-infrared (SWIR1) band (2.1\u00e2\u20ac\u201c2.35 microns).

This parameter is optional.

Output

The name of the output file to which to write the 16-bit signed (16S) spectral classification.

OutputPCT

The name of the output file to which to write the pseudocolor table (PCT) for the spectral classification.

Source background options

The pixels in the source image to be considered as background (NoData). In general, SPECL processes pixels considered NoData in a specific way.

You may specify the value for this parameter in conjunction with Source background values.

The available options for processing NoData pixels are as follows:

File metadata: Reads the NoData value from the NO_DATA_VALUE metadata of the input file. The file-level metadata tag is used as the default for each channel. Channel-level tags, when available, override the default. When metadata does not exist, all pixels of the input are considered valid.
0 {Background pixels are 0 in any channel}: Each pixel, in each channel, having a value of zero is considered NoData.
None: Each pixel, in each channel, is considered valid.
Specify values: every pixel, in every channel, having the value(s) specified in the Source Background Values parameter is considered NoData
File metadata, else specify values: Same as File Metadata, but uses the value of Source Background Values as the NoData value for each channel when metadata does not exist.

For specific examples, see the description of Source background values.

Source background values

The source background value or values when the following are specified for the Source Background Options parameter:

Specify values
File metadata, else specify values

Note: You can specify multiple values by using a comma-delimited list. The first value is applied to the first channel, the second value to the second channel, and so on. If you specify fewer values than the number of input channels, the last value is repeated for all remaining channels. If you specify more values than the number of input channels, the extra values are ignored.

For example:

File metadata, 0: Uses file-level metadata. When metadata is unavailable, pixels that have a value of zero are considered NoData.
255: Each pixel, in each channel, with a value of 255 is considered NoData.

Details

SPECL creates a spectral classification from the bands of ground-reflectance data. By default, blue, green, red, NIR, SWIR, and, optionally, SWIR1 are processed based on the wavelength sequence in the metadata.

The SWIR band has a wavelength of 1.5\u00e2\u20ac\u201c1.8 microns. The SWIR1 band has wavelength of 2.1\u00e2\u20ac\u201c2.35 microns.

This function created spectral classified 16S image and pseudo-color segment associated with it.

Spectral classification creates the following classes based on ground-reflectance data.

Invalid	100
Snow	3,000
Cloud	1,000
Bright Soil	7,000
Dark Soil	5,000
Average Vegetation	15,000
Bright Vegetation	16,000
Dark Vegetation	14,000
Yellow Vegetation	13,000
Mix Vegetation	12,000
Dry Vegetation	10,000
Sparse Vegetation	11,000
Asphalt/Dark Sand	6,000
Sand/Bare Soil/Cloud	8,000
Bright Sand	9,000
Water Turbid	4,000
Water Clear	4,300
Water over Sand	4,700

SPECL supports imagery in any GDB-supported format. For more information about GDB-supported formats, see GDB-supported file formats.

Supported sensors

Spectral classification can be processed for the following sensors:

Landsat-4 TM
Landsat-5 TM
Landsat-8
Landsat-7 ETM+
ALI
SAC-C
Sentinel-2
WorldView-3

References

Chander, G.; Markham, B.; Helder, D. Summary of Current Radiometric Calibration Coefficients for Landsat MSS, TM, ETM+ and EO-1 ALI Sensors. Remote Sensing of Environment, 113, 893-903.

Environments	PYTHON :: EASI :: MODELER
Batch Mode	Yes
Quick links	Description :: Parameters :: Parameter descriptions :: Details :: References :: Related