Author: Daniel E. Kerr
Publisher: Natural Resources Canada
Published: 2002
Total Pages: 10
ISBN-13: 0660187248
DOWNLOAD EBOOK →Both airborne & ground hyperspectral surveys have recently been undertaken as potential exploration methods for a variety of mineral deposit types in glaciated regions. This paper reviews a project that aims to summarize the surficial geology & glacial stratigraphy in the Lac de Gras kimberlite field in order to assess hyperspectral ground surveys as a drift prospecting technique for kimberlite in an area with varied overburden thickness. It describes the area's regional geology & glacial history, the reasons for lack of kimberlite indicator minerals above some kimberlite pipes, and the spectral reflectance response of bedrock exposures, kimberlite, and various till samples collected in the area. Limitations of using spectral reflectance data in drift prospecting are also discussed.
Author: H. W. O'Brien
Publisher:
Published: 1975
Total Pages: 28
ISBN-13:
DOWNLOAD EBOOK →The spectral reflectance of snow in the range of 0.60 to 2.50 micrometers wavelengths was studied in a cold laboratory using natural snow and simulated preparations of snow. A white barium sulfate powder was used as the standard for comparison. The high reflectance (usually nearly 100%) of fresh natural snow in the visible wavelength declines rapidly at wavelengths near and beyond 0.80 micrometers, as the spectral absorption coefficients of ice increase. The rate of decline of near-infrared reflectance due to aging is strongly affected by the history of the snow during aging. Snow aged under certain conditions may retain 90% or so of its reflectance in the visible red, yet may be only about 10% as reflective as the original fresh snow beyond 2.2 micrometers. Several environmental factors such as ambient temperature and wind effects which contribute to the variability in snow reflectance are discussed.
Author: Bruce Hapke
Publisher: Cambridge University Press
Published: 2012-01-19
Total Pages: 529
ISBN-13: 0521883490
DOWNLOAD EBOOK →An essential reference for researchers and students of planetary remote sensing on the interaction of electromagnetic radiation with planetary surfaces.
Author: Gustav Kortüm
Publisher: Springer Science & Business Media
Published: 2012-12-06
Total Pages: 372
ISBN-13: 3642880711
DOWNLOAD EBOOK →Reflectance spectroscopy is the investigation of the spectral composi tion of surface-reflected radiation with respect to its angularly dependent intensity and the composition of the incident primary radiation. Two limiting cases are important: The first concerns regular (specular) reflection from a smooth surface, and the second diffuse reflection from an ideal matte surface. All possible variations are found in practice between these two extremes. For the two extreme cases, two fundamentally different methods of reflectance spectroscopy are employed: The first of these consists in evaluating the optical constants n (refractive index) and x (absorption index) from the measured regular reflection by means of the Fresnel equations as a function of the wave A. This rather old and very troublesome procedure, which is length incapable of very accurate results, has recently been modified by Fahren fort by replacing the air-sample phase boundary by the phase boundary between a dielectric of higher refractive index (n ) and the sample (n ). 1 2 If the sample absorbs no radiation and the angle of incidence exceeds a certain definite value, total reflection occurs. On close optical contact between the two phases, a small amount of energy is transferred into the less dense phase because of diffraction phenomena at the edges of the incident beam. The energy flux in the two directions through the phase boundary caused by this is equal, however, so that 'total reflection takes place.
Author: Janice L. Bishop
Publisher: Cambridge University Press
Published: 2019-11-28
Total Pages: 655
ISBN-13: 110718620X
DOWNLOAD EBOOK →Comprehensive overview of the spectroscopic, mineralogical, and geochemical techniques used in planetary remote sensing.