USGS Spectral Library Version 7

Data Series 1035

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We have assembled a library of spectra measured with laboratory, field, and airborne spectrometers. The instruments used cover wavelengths from the ultraviolet to the far infrared (0.2 to 200 microns [μm]). Laboratory samples of specific minerals, plants, chemical compounds, and manmade materials were measured. In many cases, samples were purified, so that unique spectral features of a material can be related to its chemical structure. These spectro-chemical links are important for interpreting remotely sensed data collected in the field or from an aircraft or spacecraft. This library also contains physically constructed as well as mathematically computed mixtures. Four different spectrometer types were used to measure spectra in the library: (1) Beckman™ 5270 covering the spectral range 0.2 to 3 µm, (2) standard, high resolution (hi-res), and high-resolution Next Generation (hi-resNG) models of Analytical Spectral Devices (ASD) field portable spectrometers covering the range from 0.35 to 2.5 µm, (3) Nicolet™ Fourier Transform Infra-Red (FTIR) interferometer spectrometers covering the range from about 1.12 to 216 µm, and (4) the NASA Airborne Visible/Infra-Red Imaging Spectrometer AVIRIS, covering the range 0.37 to 2.5 µm. Measurements of rocks, soils, and natural mixtures of minerals were made in laboratory and field settings. Spectra of plant components and vegetation plots, comprising many plant types and species with varying backgrounds, are also in this library. Measurements by airborne spectrometers are included for forested vegetation plots, in which the trees are too tall for measurement by a field spectrometer. This report describes the instruments used, the organization of materials into chapters, metadata descriptions of spectra and samples, and possible artifacts in the spectral measurements. To facilitate greater application of the spectra, the library has also been convolved to selected spectrometer and imaging spectrometers sampling and bandpasses, and resampled to selected broadband multispectral sensors. The native file format of the library is the SPECtrum Processing Routines (SPECPR) data format. This report describes how to access freely available software to read the SPECPR format. To facilitate broader access to the library, we produced generic formats of the spectra and metadata in text files. The library is provided on digital media and online at A long-term archive of these data are stored on the USGS ScienceBase data server (

Suggested Citation

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.,

ISSN: 2327-638X (online)

Table of Contents

  • Abstract
  • Introduction
  • Spectral Library Chapters Organized by Material Type
  • Spectrometers
  • Sample Naming
  • Sample Documentation
  • Spectrometer and Purity Codes
  • Keywords Indicating Measurement Type
  • Spectral Measurement Side Effects
  • Wavelength and Bandpass Values
  • Data Precision
  • SPECPR Data Files
  • Oversampled and Convolved Versions of the USGS Spectral Library
  • Spectra and Metadata in Other Formats
  • Internet Access to the Spectral Library
  • File Names for Measured, Convolved, and Resampled Spectra
  • Acknowledgements
  • References Cited.
  • Appendix 1. Release Notes Spectral Library Version 7
  • Appendix 2. List of Abbreviations
  • Appendix 3. Metadata Templates

Additional publication details

Publication type:
Publication Subtype:
USGS Numbered Series
USGS Spectral Library Version 7
Series title:
Data Series
Series number:
Year Published:
U.S. Geological Survey
Publisher location:
Reston, VA
Contributing office(s):
Crustal Geophysics and Geochemistry Science Center
Report: iv, 61 p.; Dataset; Data Release
Online Only (Y/N):