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ENVI

Working with Metaspectral Datasets in the ENVI API

Metaspectral Datasets

Some datasets such as ASTER and Landsat ETM+ put similar bands into separate groups. These are called metaspectral datasets. Each group of bands is treated as a separate raster in ENVI.

You must specify the correct raster when using image-processing routines such as ENVIRadiometricCalibrationTask. For example, you may only want to calibrate Landsat-8 multispectral bands to radiance. Landsat-8 data are stored in a three-element array. The first element (raster[0]) contains the multispectral data from the OLI sensor. Create a variable as follows:

  MSIRaster = raster[0]

Then apply subsequent image-processing routines to MSIRaster.

The tables below list the correct array element to use when referencing specific groups of bands.

ASTER

ASTER Level-1A and Level-1B data are stored in a four-element array. Open the dataset as follows:

File = 'AST_L1B_00304102007185203_20101010013020_18032.hdf'
Raster = e.OpenRaster(File, EXTERNAL_TYPE='eos_aster')

Group

Bands

Array Element

Thermal infrared (TIR)

10-14

Raster[0]

Shortwave infrared (SWIR)

4-9

Raster[1]

Visible near-infrared (VNIR) 1

3B

Raster[2]

Visible near-infrared (VNIR) 2

1, 2, 3N

Raster[3]

Landsat 4-5 TM

Landsat TM data are stored in a two-element array. Open the dataset as follows:

File = 'LT52310671984201CUB00_MTL.txt'
Raster = e.OpenRaster(File)

Group

Bands

Array Element

Multispectral

1-5, 7

Raster[0]

Thermal

6

Raster[1]

Landsat-7 ETM+

Landsat ETM+ data are stored in a three-element array. Open the dataset as follows:

File = 'LE70340332002174EDC00_MTL.txt'
Raster = e.OpenRaster(File)

Group

Bands

Array Element

Multispectral

1-7

Raster[0]

Thermal

61-62

Raster[1]

Panchromatic

8

Raster[2]

Landsat-8

Landsat-8 data are stored in a five-element array. Open the dataset as follows:

File = 'LC80430342015121LGN00_MTL.txt'
Raster = e.OpenRaster(File)

Group

Band Names

Array Element

Multispectral (OLI)

Coastal aerosol, Blue, Green, Red, NIR, SWIR1, SWIR2

Raster[0]

Panchromatic

Panchromatic

Raster[1]

Cirrus

Cirrus

Raster[2]

Thermal (TIRS)

Thermal Infrared 1, Thermal Infrared 2

Raster[3]

Quality

Quality

Raster[4]

See Also


ENVIMetaspectralRaster

 



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