8,647 research outputs found
Application of HCMM satellite data to mineral exploration
There are no author-identified significant results in this report
Field Utilization and Analysis of AIS 128-channel Imagery Using Microcomputers: Application to Yerington, Nevada Field Area
Geologists in exploration need to be able to determine the mineral composition of a given outcrop, and then proceed to another in order to carry out the process of geologic mapping. Since April 1984 researchers have been developing a portable microcomputer-based imaging system (with a grey-scale of 16 shades of amber), which were demonstrated during the November 1984 GSA field trip in the field at Yerington, NV. A color-version of the same technology was recently demonstrated. The portable computer selected is a COLBY 10-Megabyte, hard disk-equipped repackaged-IBM/XT, which operates on either 110/220 VAC or on 12VDC from the cigarette lighter in a field vehicle. A COMPAQ PLUS or an IBM Portable will also work on modified software. The underlying concept is that the atmospheric transmission and surface albedo/slope terms are multiplicative, relating the spectral irradiance to the spectral color of the surface materials. Thus, the spectral color of a pixel remains after averaged log-albedo and log-irradiance have been estimated. All these steps can be carried out on the COLBY microcomputer, using 80 image lines of the 128-channel, 12-bit imagery. Results are shown for such an 80-line segment, showing the identification of an O-H bearing mineral group (of slightly varying specific characters) on the flight line
Multispectral signatures in relation to ground control signature using nested sampling approach
There are no author-identified significant results in this report
Feasibility of using S-191 infrared spectra for geological studies from space
There are no author-identified significant results in this report
Reevaluation of the normative minerals of Sonora Pass rock standards - University of Nevada reports 7 and 12
Chemical analyses and normative minerals of Nevada mountain pass rock
Simultaneous use of LANDSAT digital data with that of geophysical and geological surveys in geomathematical modelling for mineral exploration prediction
The author has identified the following significant results. A computer test file was created for the analysis of two rows in the pilot area. Data were organized into two groups with and without radioactivity above 1200 counts. The first 42 samples corresponded to the geographic cells which were anomalous, and the rest of the samples (70) were without anomalous values. Output analysis shows that all samples were properly classified
Geological and geothermal investigations for HCMM-derived data
An attempt was made to match HCMM- and U2HCMR-derived temperature data over two test sites of very local size to similar data collected in the field at nearly the same times. Results indicate that HCMM investigations using resolutions cells of 500 m or so are best conducted with areally-extensive sites, rather than point observations. The excellent quality day-VIS imagery is particularly useful for lineament studies, as is the DELTA-T imagery. Attempts to register the ground observed temperatures (even for 0.5 sq mile targets) were unsuccessful due to excessive pixel-to-pixel noise on the HCMM data. Several computer models were explored and related to thermal parameter value changes with observed data. Unless quite complex models, with many parameters which can be observed (perhaps not even measured (perhaps not even measured) only under remote sensing conditions (e.g., roughness, wind shear, etc) are used, the model outputs do not match the observed data. Empirical relationship may be most readily studied
Evaluation of infrared spectrophotometry for compositional analysis of lunar and planetary soils. part ii- rough and powdered surfaces
Infrared spectrophotometry evaluated for compositional analysis of lunar and planetary soil
Evaluation of AIS-2 (1986) data over hydrothermally altered granitoid rocks of the Singatse Range (Yerington) Nevada and comparison with 1985 AIS-1 data
The Airborne Imaging Spectrometer-2 (AIS-2) flights along 2 subparallel lines (bearing 013) were designed to traverse 3 major rock assemblages - the Triassic sedimentary sequence; the granitoid rocks of the Yerington batholith and the Tertiary ignimbritic ash flow and ash fall tuffs. The first 2 sites are hydrothermally altered to a quartz-sericite-tourmaline mineralogy. The first AIS-2 data set showed numerous line dropouts and a considerable number of randomly distributed dark pixels. A second decommutation reduced the dropout essentially to near zero and the dark pixels by about 75 percent. Vertical striping was removed by histogram matching, column by column. A log residual spectrum was calculated which showed the departure of a 2 x 2 pixel area from the spatially and spectrally averaged scene. A 1:1 correlation was found with the log residual AIS-2 data and a large open pit area of gypsum. An area with known sericite agreed with the overflight data, and an area known to be free of any significant amount of O-H bearing materials showed no evidence of any in the AIS-2 log residuals
Evaluation of ERTS multispectral signatures in relation to ground control signatures using a nested-sampling approach
The author has identified the following significant results. Ground measured spectral signatures of wavelength bands matching ERTS MSS were collected using a radiometer at several Californian and Nevadan sites, and directly compared with similar data from ERTS CCTs. The comparison was tested at the highest possible spatial resolution for ERTS, using deconvoluted MSS data, and contrasted with that of ground measured spectra, originally from 1 meter squares. In the mobile traverses of the grassland sites, these one meter fields of view were integrated into eighty meter transects along the five km track across four major rock/soil types. Suitable software was developed to read the MSS CCT tapes, to shadeprint individual bands with user-determined greyscale stretching. Four new algorithms for unsupervised and supervised, normalized and unnormalized clustering were developed, into a program termed STANSORT. Parallel software allowed the field data to be calibrated, and by using concurrently continuously collected, upward- and downward-viewing, 4 band radiometers, bidirectional reflectances could be calculated
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