Rowan and Wetlaufer 1975 used a Landsat mosaic of Nevada to interpret regional lineaments.Comparing the lineament patterns with ore occurrences showed that mining districts tend to occur along lineaments and are concentrated at the intersections of lineaments. Mapping of geology and fracture patterns at regional and local scales. From Sabins 1997, Table 11-3ġ3 These studies describe two different approaches to mineral exploration. Table 1 Representative mineral exploration investigations using remote sensing. The objective is to display spectral and other characteristics of the scene that are not apparent on restored and enhanced images. Information extraction utilizes the computer to combine and interact between different aspects of a data set. The objective is to improve the information content of the image. Image enhancement alters the visual impact that the image has on the interpreter. The objective is to make the restored image resemble the scene on the terrain. Sabins, 1997 groups image-processing methods into three functional categories : Image restoration compensates for image errors, noise, and geometric distortions introduced during the scanning, recording, and playback operations. Spectral reflectance curves are for vegetation and sedimentary rocks. Spectral bands recorded by remote sensing systems. Spectral bands recorded by remote sensing systemsįig. (E) Band 5, reflected IR 1.55 to 1.75 mm. Landsat TM visible and reflected IR images of Goldfield mining district, NV. A panchromatic band to 0.90 mm with spatial resolution of 15 m is added.ħ Fig. The second generation of Landsat continued with Landsat 7, launched in April, 1999, with an enhanced TM system. The image data are telemetered to earth receiving stations. Each TM scene records 170 by 185 km of terrain. Band 6 records thermal IR energy 10.5 to 12.5 mm with a spatial resolution of 120 m. These visible and reflected IR have a spatial resolution of 30 m. Landsat 6 of the second generation was launched in 1993, but failed to reach orbit.Ħ The TM system records three wavelengths of visible energy blue, green, and red (Band 1, 2 and 3) and three bands of reflected IR energy (Band 4, 5 and 7). The second generation Landsats 4, 5 and 7, which began in 1982 and continues to the present. The first generation Landsats 1, 2, and operated from 1972 to 1985. 1).Īdvantages: archives of worldwide data are readily available images cover large areas on the ground prices per square kilometer are generally lower Disadvantages : the latest hyperspectral technology is currently available only from aircraft aircraft missions can be configured to match the requirements of a projectĥ Landsat images Landsat satellites that have acquired valuable remote sensing data for mineral exploration and other applications. Sabins * Remote Sensing Enterprises, 1724 Celeste Lane, Fullerton, CA 92833, USA Received 13 November 1998 accepted 20 April 1999 From : Ore Geology Reviews –183Ģ Outline Introduction Remote sensing technology Landsat imagesĭigital image processing Mineral exploration overview Mapping hydrothermal alteration at epithermal Vein deposits - Goldfield, Nevada Summary Referencesģ Introduction Remote sensing is the science of acquiring, processing,Īnd interpreting images and related data, acquired from aircraft and satellites, that record the interaction between matter and electromagnetic energy (Sabins, 1997, p.
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