Open Access Spectral Libraries

Online resources for obtaining in situ spectral data

Source: https://hyspeedblog.wordpress.com/2013/07/12/open-access-spectral-libraries-online-resources-for-obtaining-in-situ-spectral-data/

There are many different analysis techniques used in remote sensing, ranging from the simple to complex. In imaging spectrometry, i.e. hyperspectral remote sensing, a common technique is to utilize measured field or laboratory spectra to drive physics-based image classification and material detection algorithms.

Here the measured spectra are used as representative examples of the materials and species that are assumed present in the remote sensing scene.

Spectral analysis techniques can then be used to ascertain the presence, distribution and abundance of these materials and species throughout an image.

In most cases the best approach is to measure field spectra for a given study area yourself using a field-portable spectrometer; however, the time and cost associated with such fieldwork can oftentimes be prohibitive.

Another alternative is to utilize spectral libraries, which contain catalogs of spectra already measured by other researchers.

Below are examples of open access spectral libraries that are readily available online:

• The ASTER Spectral Library, hosted by the Jet Propulsion Laboratory (JPL), contains a compilation of three other libraries, the Johns Hopkins University Spectral Library, the JPL Spectral Library and the USGS Spectral Library. The ASTER library currently contains over 2400 spectra and can be ordered in its entirety via CD-ROM or users can also search, graph and download individual spectra online.


• The SPECCHIO Spectral Library is an online database maintained by the Remote Sensing Laboratories in the Department of Geography at University of Zurich. Once users have registered with the system to create an account, the SPECCHIO library can be accessed remotely over the internet or alternatively downloaded and installed on a local system. The library is designed specifically for community data sharing, and thus users can both download existing data and upload new spectra.


• The Vegetation Spectral Library was developed by the Systems Ecology Laboratory at the University of Texas at El Paso with support from the National Science Foundation. In addition to options to search, view and download spectra, this library also helpfully includes photographs of the actual species and materials from which the data was measured. Registered users can also help contribute data to further expand the archive.


• The ASU Spectral Library is hosted by the Mars Space Flight Facility at Arizona State University, and contains thermal emission spectra for numerous geologic materials. While the library is designed to support research on Mars, the spectra are also applicable to research closer to home here on Earth.


• The Jet Propulsion Laboratory is currently building the HyspIRI Ecosystem Spectral Library. This library is still in its development phase, and hence contains only a limited number of spectra at this time. Nonetheless, it is expected to grow, since the library was created as a centralized resource for the imaging spectrometry community to contribute and share spectral measurements.

Searching for other remote sensing data resources? Check out these earlier posts on resources for obtaining general remote sensing imagery as well as imaging spectrometry and lidar data.

HyspIRI Ecosystem Spectral Library

The HyspIRI Ecosystem Spectral Library is a compilation of data from other Ecosystem spectral libraries.

If you use data from the HyspIRI Ecosystem Spectral Library in a publication we ask that you reference the contact person within the spectral library.

Reproduced from the HyspIRI Ecosystem Spectral Library through the courtesy of the Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California. Copyright © 1999, California Institute of Technology. ALL RIGHTS RESERVED.

Contact information:

Cognizant Scientist: Simon.J.Hook@jpl.nasa.gov

ALL RIGHTS RESERVED Copyright California Institute of Technology U.S. Government Sponsorship Acknowledged under NAS7-1260 CL 12-0980

Source: https://hesl.jpl.nasa.gov/

The Johns Hopkins Library (Spectral)

With the exception of man made materials, all spectra in the Johns Hopkins Library were measured under the direction of John W. (Jack) Salisbury. Most measurements were made by Dana M. D'Aria, either at Johns Hopkins University in Baltimore, MD, or at the U.S. Geological Survey in Reston, VA.

This text is a general introduction to the library, with an overview of Measurement techniques, which do differ for different materials.

There is a separate introductory text for each kind of material (rocks, minerals, lunar soils, terrestrial soils, man made materials, meteorites, vegetation, snow&ice, etc.) that contains more specific information pertinent to that material.

Any questions concerning the Johns Hopkins Library can be e-mailed to Jack Salisbury at salisburys@worldnet.att.net...

All other spectral data, with the exception of portions of generic snow and vegetation spectra (see the introductory text for each type of material), were measured in directional hemispherical reflectance.

Under most conditions, the infrared portion of these data can be used to calculate emissivity using Kirchhoff's Law (E=1-R), which has been verified by both laboratory and field measurements (Salisbury et al., 1994; Korb et al., 1996).

The unusual circumstances (e.g., the lunar environment) where thermal gradients may cause significant departure from Kirchhoffian behavior are discussed in Salisbury et al., 1994.

The apparently seamless reflectance spectra from 0.4 to 14 micrometers (microns) of Rocks and soils were generated using two different instruments, both equipped with integrating spheres for measurement of directional hemispherical reflectance, with source radiation impinging on the sample from a center line angle 10 degrees from the vertical.

Source: https://speclib.jpl.nasa.gov/documents/jhu_desc

ASTER Spectral Library - Version 2.0

The ASTER spectral library, a compilation of over 2400 spectra of natural and man made materials. Version 2.0 of the ASTER spectral library was released on December 3rd, 2008.

The ASTER spectral library includes data from three other spectral libraries:

the Johns Hopkins University (JHU) Spectral Library
the Jet Propulsion Laboratory (JPL) Spectral Library, and
the United States Geological Survey (USGS - Reston) Spectral Library.

If you use data from the ASTER spectral library in a publication we ask that you reference the following article: Baldridge, A. M., S.J. Hook, C.I. Grove and G. Rivera, 2009. The ASTER Spectral Library Version 2.0. Remote Sensing of Environment, vol 113, pp. 711-715.

Reproduced from the ASTER Spectral Library through the courtesy of the Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California. Copyright © 1999, California Institute of Technology. ALL RIGHTS RESERVED.

Contact information:
Cognizant Scientist: Simon.J.Hook@jpl.nasa.gov