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