Thermal Infrared Emissivity in Satellite Mineral Exploration

“Determining mineralogical variations of aeolian deposits using thermal infrared emissivity and linear deconvolution methods” By: Bernard E. Hubbard ORCID iD , Donald M. Hooper, Federico Solano, and John C. Mars https://doi.org/10.1016/j.aeolia.2017.12.001

Abstract (Edited for easier online reading)

Fig. 4. Microphotographs
Fig. 4. Microphotographs for the 2-phi sieved size fraction of the eight sand samples

We apply linear deconvolution methods to derive mineral and glass proportions for eight field sample training sites at seven dune fields

(1) Algodones, California;
(2) Big Dune, Nevada;
(3) Bruneau, Idaho;
(4) Great Kobuk Sand Dunes, Alaska;
(5) Great Sand Dunes National Park and Preserve, Colorado;
(6) Sunset Crater, Arizona; and
(7) White Sands National Monument, New Mexico.

These dune fields were chosen because they represent a wide range of mineral grain mixtures and allow us to gauge a better understanding of both compositional and sorting effects within terrestrial and extraterrestrial dune systems.

We also use actual ASTER TIR emissivity imagery to map the spatial distribution of these minerals throughout the seven dune fields and evaluate the effects of degraded spectral resolution on the accuracy of mineral abundances retrieved.

Our results show that hyperspectral data convolutions of our laboratory emissivity spectra outperformed multispectral data convolutions of the same data with respect to the mineral, glass and lithic abundances derived.

Both the number and wavelength position of spectral bands greatly impacts the accuracy of linear deconvolution retrieval of feldspar proportions (e.g. K-feldspar vs. plagioclase) especially, as well as the detection of certain mafic and carbonate minerals.

In particular, ASTER mapping results show that several of the dune sites display patterns such that less dense minerals typically have higher abundances near the center of the active and most evolved dunes in the field, while more dense minerals and glasses appear to be more abundant along the margins of the active dune fields.

Source: https://pubs.er.usgs.gov/publication/70194839

Authors: Bernard E.Hubbarda, Donald M.Hooperb1, FedericoSolanoa, John C.Marsa

a U.S. Geological Survey, 12201 Sunrise Valley Drive, Reston, VA 20192, United States
b Geosciences and Engineering Division, Southwest Research Institute®, San Antonio, TX 78238-5166, United States

Received 21 October 2017, Revised 5 December 2017, Accepted 5 December 2017, Available online 29 December 2017.

Full article online at: https://www.sciencedirect.com/science/article/pii/S1875963717301982?via%3Dihub#!

About ASTER

Designed to capture high-resolution images of Earth, the Advanced Spaceborne Thermal Emission and Reflection Radiometer, or ASTER, instrument is one of five instruments aboard NASA’s Terra satellite. The instrument’s data are used to create detailed maps of land surface temperature, emissivity, reflectance and elevation on Earth.

The Advanced Spaceborne Thermal Emission and Reflection Radiometer obtains high-resolution (15 to 90 square meters per pixel) images of the Earth in 14 different wavelengths of the electromagnetic spectrum, ranging from visible to thermal infrared light. Scientists use ASTER data to create detailed maps of land surface temperature, emissivity, reflectance, and elevation.

ASTER is the only high spatial resolution instrument on the Terra platform. ASTER’s ability to serve as a ‘zoom’ lens for the other Terra instruments is particularly important for change detection, calibration/validation and land surface studies.

Unlike the other instruments aboard Terra, ASTER will not collect data continuously; rather, it collects an average of 8 minutes of data per orbit.

All three ASTER telescopes (VNIR, SWIR, and TIR) are pointable in the crosstrack direction. Given its high resolution and its ability to change viewing angles, ASTER produces stereoscopic images and detailed terrain height models.

Images taken by the ASTER instrument also provide detailed views of the effects of global climate change and extreme weather on Earth’s landforms and topography.

https://asterweb.jpl.nasa.gov

ASTER Spectral Library – Version 2.0 – https://speclib.jpl.nasa.gov/