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U.S. Geological Survey (USGS) Spectral Library Version 7 Data

Kokaly, R.F., Clark, R.N., Swayze, G.A., Livo, K.E., Hoefen, T.M., Pearson, N.C., Wise, R.A., Benzel, W.M., Lowers, H.A., Driscoll, R.L., and Klein, A.J., 2017, USGS Spectral Library Version 7: U.S. Geological Survey Data Series 1035, 61 p., https://doi.org/10.3133/ds1035.

The USGS publication cited above describes the instruments used, measurement procedures, contents of metadata descriptions of spectra and samples, and possible artifacts in the spectra. Please reference any use of these data with the above citation. The 2,457 spectra in version 7 of the library cover wavelengths from the ultraviolet to the far infrared regions of the electromagnetic spectrum (0.2 to 200 µm). The library has grown from its initial release in 1993 to now include 1,497 spectra of mineral samples, grain size fractions, coatings, and mixtures. The library has expanded to include spectra of other substances, including vegetation, plant biochemical constituents, organic compounds, and manmade materials.

This interactive website allows user to search the contents of the library. Spectra are provided in ASCII data files (with .txt extension). The HTML-formatted metadata descriptions are also provided as text files with .html extension. Plots of the spectra were created and stored as GIF images with .gif extension.  For each spectrum, a zip file containing the ASCII, HTML, and GIF files can be downloaded (see the “Zip” link in the far-right column). The zip files also contain the associated wavelength and bandpass data, which are stored in separate files.

In addition to the original measured spectra, the library also includes convolved and resampled versions of spectra for selected laboratory spectrometers (ASD), imaging spectrometers (AVIRIS-Classic, HyMap, Hyperion, CRISM, M3, and VIMS), and broad band multispectral sensors (ASTER, Landsat8 OLI, Sentinel-2 MSI, and WorldView-3). See the links and drop-down selections in the black menu bar at the top of the page.
Spectra were divided into sub-categories (described as library chapters) by material type:

• Minerals

• Soils and mineral mixtures

• Coatings

• Liquids

• Organic compounds

• Artificial materials

• Vegetation and other biologic materials

• Wavelength and Bandpass

On-line Spectral Library Functionality:

• Change to a small-screen friendly data listing mode by clicking the gear icon and selecting "Cards" from the "View Mode" drop-down menu.

• Sort by column by clicking on the column heading or by clicking the custom sort icon .

• Filter by Chapter by clicking the funnel icon next to the Chapter heading.

• Change pagination setings or view all records by clicking the gear icon .

• Use "Quick Search" to filter on full or partial terms in the data listing .

• Mouse hover over icons for icon descriptors.

• Select items using the checkbox on the left hand side of the listing to compare records in a seperate view.

Contact:

Raymond F. Kokaly (USGS), raymond@usgs.gov