Search NASA⌕ Search

SEARCH · Search NASA

Results for “county”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 199 records · Page 11

Correlation of LANDSAT lineaments with Devonian gas fields in Lawrence County, Ohio

In an effort to locate sources of natural gas in Ohio, the fractures and lineaments in Black Devonian shale were measured by: (1) field mapping of joints, swarms, and fractures; (2) stereophotointerpretation of geomorphic lineaments with precise photoquads; and (3) by interpreting the linear features on LANDSAT images. All results were compiled and graphically represented on 1:250,000 scale maps. The geologic setting of Lawrence County was defined and a field fracture map was generated and plotted as rose patterns at the exposure site. All maps were compared, contrasted, and correlated by superimposing each over the other as a transparency. The LANDSAT lineaments had significant correlation with the limits of oil and gas producing fields. These limits included termination of field production as well as extensions to other fields. The lineaments represent real rock fractures with zones of increased permeability in the near surface bedrock.

Johnson, G. O.↗

Land cover analysis of James City County, Virginia

The approach used to obtain reliable countywide forest resource data, including statistics and a forest cover distribution map from LANDSAT data is described. Comparison of results of the LANDSAT anlysis and U.S. Forestry Survey data is presented in a table. Pine, oak/pine, and oak/hickory accounted for 22.3%, 32.6% and 45.2% respectively of the total forest area in the LANDSAT analysis, compared to 22.8%, 30.1%. and 47.1% in the Forest Survey. The corresponding figures for each forest type differ at most 2.5% for the mixed forest. The total county area in forest land measured using LANDSAT was underestimated by 1,409 acres, a 2.2% error based on the Forest Survey statistics. However, the estimate of 61,242 acres fell well within the known 4% uncertainty of the estimate for the Forest Survey figures (62,651 acres + or - 2,544 acres).

Copony, J. A.↗

Monitoring strip mining and reclamation with LANDSAT data in Belmont County, Ohio

The utility of LANDSAT digital data for mapping and monitoring surface mines in Belmont County, Ohio was investigated. Two data sets from 1976 and 1979 were processed to classify level 1 land covers and three strip mine categories in order to examine change over time and assess reclamation efforts. The two classifications were compared with aerial photographs. Results of the accuracy assessment show that both classifications are approximately 86 per cent correct, and that surface mine change detection (date-to-date comparison) is facilitated by the digital format of LANDSAT data.

Witt, R. G.↗

Wildland inventory and resource modeling for Douglas and Carson City Counties, Nevada, using LANDSAT and digital terrain data

The potential of using LANDSAT satellite imagery to map and inventory pinyon-juniper desert forest types in Douglas and Carson City Counties, Nevada was demonstrated. Specific map and statistical products produced include land cover, mechanical operations capability, big game winter range habitat, fire hazard, and forest harvestability. The Nevada Division of Forestry determined that LANDSAT can produce a reliable and low-cost resource data. Added benefits become apparent when the data are linked to a geographical information system (GIS) containing existing ownership, planning, elevation, slope, and aspect information.

Brass, J. A.↗

Final Comparison of TM and MSS Data for Surface Mine Assessment in Logan County, West Virginia

A variety of classifications during both raw and transformed MSS and TM data sets from 4 September 1982 were performed for the Logan County, West Virginia study area. The object was to compare the utility of TM and MSS data for delineating small, irregular ground features, particularly surface mines, and also to test data reduction/transformation techniques (band selection, canonical analysis, and principal components) in relation to a traditional means of unsupervised classification. Statistical results demonstrate that, on the average, the TM classifications yielded an overall .53 factor of improvement relative to the MSS classifications. When the accuracies for only three minor (in terms of areal extent) land use categories are examined, the factor of improvement for TM over MSS increases to 1.48; i.e., the TM is nearly one and one-half times better than the MSS for delineating small and irregular ground features such as contour strip mines.

Witt, R. G.↗

Analysis of Landsat-4 Thematic Mapper data for classification of forest stands in Baldwin County, Alabama

A computer-implemented classification has been derived from Landsat-4 Thematic Mapper data acquired over Baldwin County, Alabama on January 15, 1983. One set of spectral signatures was developed from the data by utilizing a 3x3 pixel sliding window approach. An analysis of the classification produced from this technique identified forested areas. Additional information regarding only the forested areas. Additional information regarding only the forested areas was extracted by employing a pixel-by-pixel signature development program which derived spectral statistics only for pixels within the forested land covers. The spectral statistics from both approaches were integrated and the data classified. This classification was evaluated by comparing the spectral classes produced from the data against corresponding ground verification polygons. This iterative data analysis technique resulted in an overall classification accuracy of 88.4 percent correct for slash pine, young pine, loblolly pine, natural pine, and mixed hardwood-pine. An accuracy assessment matrix has been produced for the classification.

Hill, C. L.↗

Development and testing of a rural credit supervision system at the level of counties and rural properties utilizing remote sensing techniqes

Remote sensing techniques for supporting the rural credit supervision system were developed and tested. The test area comprised the counties of Aracatuba and Guararapes, located in the State of Sao Paulo. Aerial photography, LANDSAT images and topographic charts were used. Aerial photographs were extremely useful for the out lining of properties boundaries with financing of sugarcane plantations by the Banco do Brasil S.A.. The percentage of correctly interpreted sugarcane on LANDSAT images, considering the 85 analyzed properties, was of 63.12%. The occurrence of atypical conditions such as excessive raining, sugarcane in bloom, and wind damaged sugarcane and sugarcane not harvested due to planning failures verified during the period the images were obtained, were some of the contributing factors associated with a low interpretation performance. An alternative approach was developed using several LANDSAT overpasses and auxiliary field data, which resulted in 91.77 percent correct.

Batista, G. T.↗

Comparative techniques used to evaluate Thematic Mapper data for land cover classification in Logan County, West Virginia

Several digital data processing techniques were evaluated in an effort to identify and map active/abandoned, partially reclaimed, and fully revegetated surface mine areas in the central portion of Logan County. The TM data were first subjected to various enhancement procedures, including a linear contrast stretch, principal components and canonical analysis transformations. At the same time, four general procedures were followed to produce six classifications as a means of comparing the techniques involved. Preliminary results show that various feature extraction/data reduction techniques provide classification results equal or superior to the more straightforward unsupervised clustering technique. Analyst interaction time for labelling clusters is reduced using the canonical analysis and principal components procedures, though the canonical technique has clearly produced better results to date.

Brumfield, J. O.↗

Landsat thematic mapper (TM) soil variability analysis over Webster County, Iowa

Thematic mapper simulator (TMS) data acquired June 7, June 23, and July 31, 1982, and Landsat thematic mapper (TM) data acquired August 2, September 3, and October 21, 1982, over Webster County, Iowa, were examined for within-field soil effects on corn and soybean spectral signatures. It was found that patterns displayed on various computer-generated map products were in close agreement with the detailed soil survey of the area. The difference in spectral values appears to be due to a combination of subtle soil properties and crop growth patterns resulting from the different soil properties. Bands 4 (0.76-.90 micron), 5 (1.55-1.75 micron), and 7 (2.08-2.35 micron) were found to be responding to the within-field soil variability even with increasing ground cover. While these results are preliminary, they do indicate that the soil influence on the vegetation is being detected by TM and should provide improved information relating to crop and soil properties.

Thompson, D. R.↗

Recovery and classification of thirty new meteorites from Roosevelt County, New Mexico

The discovery and classification of 30 new meteorites found in or close to Roosevelt County, NM, are reported, including two H3 chondrites and a ureilite; the others are equilibrated ordinary chondrites. Over 160 meteorites representing at least 100 different falls have been recovered from this region, mostly from wind blowout areas. As in Antarctica, small specimens predominate and irons, achondrites, and C and E chondrites are rare. Paired specimens are also very difficult to identify.

Scott, E. R. D.↗

Accretion, metamorphism, and brecciation of ordinary chondrites - Evidence from petrologic studies of meteorites from Roosevelt County, New Mexico

The olivines and pyroxenes from twenty-nine ordinary chondrites from Roosevelt County, New Mexico are examined. The mineralogical properties of the chondrites studied are described. Correlations between mineral compositions and petrologic type and between petrologic type and bulk chemistry are analyzed. It is observed that mean CaO concentrations in olivine show significant variations among equilibrated chondrites, but these are not correlated with petrologic type; the degree of heterogeneity of FeO concentrations in olivines of types 4-6 is not correlated with the degree of metamorphism; and mean FeO concentrations of silicates show average increases of 3-5 percent from type 4 to type 6 in each group.

Scott, Edward R. D.↗

Survey for least bell's vireo in riparian habitat on Vandenberg Air Force Base, Santa Barbara County, California

The least bell's vireo (Vireo bellii pusillus) was listed in 1986 as an endangered species by the U.S. Fish and Wildlife Service. Because of the possibility of the species existing on Vandenberg Air Force Base (VAFB), this survey was conducted to determine if they exist, and if so to prepare a distribution map of the species on the base. Major riparian areas were surveyed on foot for 17 days in April, May, and July 1987. No least bell's vireo were sighted; based on past studies, it is unlikely that there is a significant population on VAFB. There are, however, at least 13 other species of special concern that inhabit VAFB riparian woodlands. Most of these species have declined along the south coast of Santa Barbara County, and many have declined in much of the southern half of California. Riparian areas on VAFB are an important environmental resource for the southern half of California; many of these areas, however, show signs of degradation.

Breininger, David R.↗

NASA applications project in Miami County, Indiana

This project was designed to acquaint county government officials and their clientele with remote sensing and geographic information systems (GIS) products that contain information about land conditions and land use. The specific project objectives are: (1) to investigate the feasibility of using remotely sensed data to identify and quantify specific land cover categories and conditions for purposes of tax assessment, cropland area measurements, and land use evaluation; (2) to evaluate the use of remotely sensed data to assess soil resources and conditions which affect productivity; (3) to investigate the use of satellite remote sensing data as an aid in assessing soil management practices; and (4) to evaluate the market potential of products derived from the above projects.

Johannsen, Chris J.↗

Spinel-bearing, Al-rich chondrules in two chondrite finds from Roosevelt County, New Mexico - Indicators of nebular and parent body processes

Two rare spinel-bearing Al-rich chondrules are identified in chondrite finds from Roosevelt County, New Mexico-RC 071 (L4) and RC 072 (L5). These chondrules have unusual mineralogies dominated by highly and asymmetrically zoned Al-Cr-rich spinels. Two alternatives exist to explain the origin of this zoning-fractional crystallization or metamorphism. Fractional crystallization formed the zoning of the trivalent cations and caused a localized depletion in chromites around the large Al-Cr-rich spinels. Diffusive exchange and partitioning of Fe and Mg between olivine and spinel during parent-body metamorphism can explain the asymmetric zoning of these elements. The bulk compositions of the chondrules suggest affinities with the Na-Al-Cr-rich chondrules, as would be expected from the abundance of Al-Cr-rich spinels. The most important factors are the temperature to which the molten chondrule was heated and the cooling rate during crystallization. These two chondrules cooled rapidly from near the liquidus, as indicated by the zoning, occurrence and sizes of spinels, radiating chondrule textures and localized chromite depletions.

Mccoy, Timothy J.↗

Quantitative remote sensing of ammonium minerals, Cedar Mountains, Esmeralda County, Nevada

Mineral-bound ammonium (NH4+) was discovered by the U.S. Geological Survey in the southern Cedar Mountains of Esmeralda County, Nevada in 1989. At 10 km in length, this site is 100 times larger than any previously known occurrence in volcanic rocks. The ammonium occurs in two hydrothermally altered, crystal-rich rhyolitic tuff units of Oligocene age, and is both structurally and stratigraphically controlled. This research uses Advanced Visible/Infrared Imaging Spectrometer (AVIRIS) data to quantitatively map the mineral-bound ammonium (buddingtonite) concentration in the altered volcanic rocks. Naturally occurring mineral-bound ammonium is fairly rare; however, it has been found to occur in gold-bearing hydrothermal deposits. Because of this association, it is thought that ammonium may be a useful too in exploration for gold and other metal deposits. Mineral-bound ammonium is produced when an ammonium ion (NH4+) replaces the alkali cation site (usually K+) in the crystal structure of silicate minerals such as feldspars, micas and clays. Buddingtonite is an ammonium feldspar. The ammonium originates in buried organic plant matter and is transported to the host rock by hydrothermal fluids. Ammonium alteration does not produce visible changes in the rock, and it is barely detectable with standard x-ray diffraction methods. It is clearly identified, however, by absorption features in short wave-infrared (SWIR) wavelengths (2.0 - 2.5 micrometers). The ammonium absorption features are believed to be caused by N-H vibrational modes and are analogous to hydroxyl (O-H) vibrational modes, only shifted slightly in wavelength. Buddingtonite absorption features in the near- and SWIR lie at 1.56, 2.02 and 2.12 micrometers. The feature at 2.12 micrometer is the strongest of the three and is the only one used in this study. The southern Cedar Mountains are sparsely vegetated and are an ideal site for a remote sensing study.

Baugh, William M.↗

Roosevelt County 075: A petrologic chemical and isotopic study of the most unequilibrated known H chondrite

Roosevelt County (RC) 075 was recovered in 1990 as a single 258-gram stone. Classification of this meteorite is complicated by its highly unequilibrated nature and its severe terrestrial weathering, but we favor H classification. This is supported by O isotopes and estimates of the original Fe, Ni metal content. The O isotopic composition is similar to that of a number of reduced ordinary chondrites (e.g., Cerro los Calvos, Willaroy), although RC 075 exhibits no evidence of reduced mineral compositions. Chondrule diameters are consistent with classification as an L chondrite, but large uncertainties in chondrule diameters of RC 075 and poorly constrained means of H, L and LL chondrites prevent use of this parameter for reliable classification. Other parameters are compromised by severe weathering (e.g., siderophile element abundances) or unsuitable for discrimination between unequilibrated H, L and LL chondrites (e.g., Co in kamacite delta C-13). Petrologic subtype 3.2 +/- 0.1 is suggested by the degree of olivine heterogeneity, the compositions of chondrule olivines, the thermoluminescence sensitivity, the abundances and types of chondrules mapped on cathodoluminescence mosaics, and the amount of presolar SiC. The meteorite is very weakly shocked (S2), with some chondrules essentially unshocked and, thus, is classified as an H3.2(S2) chondrite. Weathering is evident by a LREE enrichment due to clay contamination, reduced levels of many siderophile elements, the almost total loss of Fe, Ni metal and troilite, and the reduced concentrations of noble gases. Some components of the meteorite (e.g., type IA chondrules, SiC) appear to preserve their nebular states, with little modification from thermal metamorphism. We conclude that RC 075 is the most equilibrated H chondrite yet recovered and may provide additional insights into the origin of primitive materials in the solar nebula.

Mccoy, T. J.↗