Hyperion Hyperspectral pre-processing

Transferred from: Export tools V2.0

This is a free ENVI extension tool that is used to read, correct, and use the l1r, l1g/l1t-level epoch. To facilitate the use of data, the most basic function is to use the l1r tool.
HDF and l1g/l1t geotiff data are converted into an ENVI file that contains the central wavelength, wavelength radius, and bad band information. The format of each input data also contains some options, including striped noise repair, mask file generation, and so on, which will be more useful when using data from the company.

Tool: http://115.com/file/c25kvb9p

Tool installation method:

1. Put the hyperion_tools.savand hyperion_wl_fwhm_bbl.txt files in the save_add folder under your ENVI installation directory, and then restart envi.

2. Put the hyperion_tools.savand hyperion_wl_fwhm_bbl.txt files in the ENVI installation directory exelis \ envi50 \ extensions or exelis \ envi50 \ classic \ save_add.

In envi4.8 and earlier versions, as well as the classic version of envi5.0, go to this tool through file-> open external file-> EO-1-> company tools.

In envi5.0, you can find this tool in toolbox-> extensions.

The operation of this tool is very simple. The following describes its basic usage and main functions:

• L1r data

Click "input HDF" and select the l1r file. Click "output path" to select a folder for storing data in the new ENVI format. Click "process" to perform conversion. In this mode, the conversion tool will place the raw radiation data in the new files of the BIL format ENVI, including the average wavelength and FWHM value. The generated new file has the same file name as the input HDF.

 

 

 

Figure 1: l1r options

Other options have the following functions:

Attempt georeferencing: If the metadata file (. met) and l1r HDF are packaged together, that is, they are in the same folder as HDF files and have the same file name as HDF, the toolkit will list the geographical coordinates of the four corners in the new ENVI format file. Projection is only a pseudo-geographic projection, and not all metadata files contain coordinates of Four Corners. Therefore, sometimes georeferencing cannot be performed.

Use flag mask correction: a small number of epoch detectors may fail, which often leads to vertical "stripes" on all band images ". This option can be called to replace the bad value by taking the average value of the bad value on both sides, so as to remove the "stripe". This correction is performed when the raw data is restored from HDF.
The fly is stored in the newly generated ENVI format file.

Output ENVI mask image: This option enables the toolkit to create an ENVI mask image (1 = good data, 0 = bad data) for the dataset to suppress the black background that appears in the reference image. This option is particularly useful when PCA, Fourier transformation, and hourglass processing is performed with raw data without Flag corrected. The mask image and the converted data file have the same basic
Rootname, but it is followed by "_ mask. dat ".

Output wavelength/FWHM tables: output the center wavelength and wavelength radius of each band to a table.

Output flaash scale factors: a small text file is generated in a specific output folder, which contains a proportional coefficient. This coefficient is required to correctly input the data from the input to the flaash.

Interpolate data to common wavelength set: each detector in the FEP array has a slightly different band center and FWHM value in each band. This option performs linear interpolation on pixels, spectra, and bands for all detectors based on normal wavelength settings (a common set of wavelength. In this process, the bad band list should also be listed to ensure the best results. Warning the interpolation process can take up to one hour for full execution. This option accepts the conversion data file and creates a new BIP output file. This new file has the same root directory file name (Basic
Rootname), but it is followed by "_ interpolated. dat ". The included wavelength represents the normal value of the new band center (Common set ). The average value is FWHM.

• L1g/1t Option

For l1g/1t data, click "input MTL" and select "l1g" or "l1t" as the metadata file. They are packaged together with the geotiff file. Click "output path" to select a storage folder for the new ENVI data format, and click "process" to convert the data. In this mode, the conversion tool will place the original radiation data in the new ENVI file in bsq format, including the average wavelength and FWHM value. The generated new file has the same file name as the input geotiffs, but the extension is ". dat ". To complete the conversion, All 242 geotiff files must be in the same folder as MTL metadata files.

 

 

 

Figure 2: l1g/1t Option

Other options have the following functions:

Output ENVI mask image: This option enables the tool to create an ENVI mask image (1 = good data, 0 = bad data) for the dataset to suppress the black background that appears in the reference image. This option is useful for almost all ENVI processing, because the background value does not belong to the original dataset. The mask image and the converted data file have the same basic
Rootname, but it is followed by "_ mask. dat ".

Ouput flaash scale factors: a small text file is generated in a specific output folder, which contains a proportional coefficient. This coefficient is necessary for correct input of the company's data to the flaash for atmospheric correction, used for conversion of radiation rate units.

Output interleav: As ENVI combines the input geotiffs into a comprehensive output file, the initial crossover mode is bsq. Flash and other spectral processing methods tend to or require the BIL or BIP crossover mode. This option converts the output file to bip format (new files are generated during processing) and then deletes the original data. The generated new file has the same basic as the converted data file.
Rootname, but it is followed by "_ Bip. dat ".