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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.

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At least 145 records · Page 8
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Land use classification using texture information in ERTS-A MSS imagery

The author has identified the following significant results. Preliminary digital analysis of ERTS-1 MSS imagery reveals that the textural features of the imagery are very useful for land use classification. A procedure for extracting the textural features of ERTS-1 imagery is presented and the results of a land use classification scheme based on the textural features are also presented. The land use classification algorithm using textural features was tested on a 5100 square mile area covered by part of an ERTS-1 MSS band 5 image over the California coastline. The image covering this area was blocked into 648 subimages of size 8.9 square miles each. Based on a color composite of the image set, a total of 7 land use categories were identified. These land use categories are: coastal forest, woodlands, annual grasslands, urban areas, large irrigated fields, small irrigated fields, and water. The automatic classifier was trained to identify the land use categories using only the textural characteristics of the subimages; 75 percent of the subimages were assigned correct identifications. Since texture and spectral features provide completely different kinds of information, a significant increase in identification accuracy will take place when both features are used together.

Haralick, R. M.↗
NASA NTRS1973

Principal sources and dispersal patterns of suspended particulate matter in nearshore surface waters of the northeast Pacific Ocean and the Hawaiian Islands

The author has identified the following significant results. ERTS-1 multispectral scanner imagery of the nearshore surface waters of the Northeast Pacific Ocean is proving to be a useful tool for determining source and dispersal of suspended particulate matter. The principal sources of the turbid water, seen best on the green and red bands, are river and stream effluents and actively eroding coastlines; secondary sources are waste effluents and production of planktonic organisms, but these may sometimes be masked by the very turbid plumes of suspended sediment being discharged into the nearshore zone during times of high river discharge. The configuration and distribution of the plumes of turbid water also can be used to infer near-surface current directions. Comparison of imagery of the nearshore water off the northern California coast from October 1972 and January 1973 shows a reversal of the near-surface currents, from predominantly south-setting in the fall (California Current) to north-setting in the winter (Davidson Current).

Carlson, P. R.↗
NASA NTRS1973

Geological and geophysical remote sensing of Iceland

The author has identified the following significant results. A binational, multidisciplinary research effort in Iceland is directed at an analysis of MSS imagery from ERTS-1 to study a variety of geologic, hydrologic, oceanographic, and agricultural phenomena. Initial findings are: (1) recent lava flows can be delineated from older ones; (2) ERTS-1 and NOAA-2 recorded volcanic eruptions on Heimaey, Vestmann Islands; (3) coastline changes are mappable; (4) areas covered with new or residual snow can be mapped, and dark appearance of newly fallen snow on band 7 appears to be related to melting; (5) sediment plumes from discharge of glacial rivers can be delineated; (6) the area encompassed by glacial ice can be mapped, including the new position of a surging glacier, Eyjabakkajokull, and related phenomena of nunataks and moraines; (7) changes in position of rivers, lake sizes, and new lakes can be mapped; (8) low sun angle imagery enhances the morphologic expression of constructional glacial and volcanic landforms; (9) MSS color composites permit regional mapping of distribution of vegetation; and (10) at least at 1:250, 000 map scale and smaller, ERTS-1 imagery provides a means of updating various types of maps of Iceland and will permit the compilation of maps specifically aimed at those dynamic environmental phenomena which impact on the Icelandic economy.

Williams, R. S., Jr.↗
NASA NTRS1973

The cartographic application of ERTS/RBV imagery in polar regions

The author has identified the following significant results. Experiments have demonstrated the feasibility of revising coastlines on maps of Antarctica, detected gross changes in the northern limits of the three largest ice shelves in the world, and led to the discovery of uncharted mountain ranges. A strip photomosaic compiled at a scale of 1:1,000,000 along the Victoria Land Coast between Cape Adare and Harboard Glacier shows obvious changes in size, shape, and position of such features as glaciers, ice tongues, ice shelves, and fast ice. Similar changes to features in the Thwaites Glacier Tongue area were also discovered. Comparison of existing maps and photographs with ERTS-1 imagery over portions of the Ross and Filchner-Ronne Ice Shelves reveals that their northern limits have advanced about 6 and 15 km respectively in 7 years. Imagery also revealed new and unmapped geographical features, of which some are mountains, in the area of the recently published Australian 1:1,000,000 IMW sheet SS 40-42 and USGS IMW sheet ST 57-60 which is presently in final stages of compilation. Comparison of one ERTS-1 scene with a recently published USGS map disclosed a unique change in the Erebus Glacier Tongue. Indications are that its present position is about the same as it was in 1910.

Macdonald, W. R.↗
NASA NTRS1973

Satellite geological and geophysical remote sensing of Iceland: Preliminary results from analysis of MSS imagery

A binational, multidisciplinary research effort in Iceland is directed at an analysis of MSS imagery from ERTS-1 to study a variety of geologic, hydrologic, oceanographic, and agricultural phenomena. A preliminary evaluation of available MSS imagery of Iceland has yielded several significant results - some of which may have direct importance to the Icelandic economy. Initial findings can be summarized as follows: (1) recent lava flows can be delineated from older flows at Askja and Hekla; (2) MSS imagery from ERTS-1 and VHRR visible and infrared imagery from NOAA-2 recorded the vocanic eruption on Heimaey, Vestmann Islands; (3) coastline changes, particularly changes in the position of bars and beaches along the south coast are mappable; and (4) areas covered with new and residual snow can be mapped, and the appearance of newly fallen snow on ERTS-1, MSS band 7 appears dark where it is melting. ERTS-1 imagery provides a means of updating various types of maps of Iceland and will permit the compilation of special maps specifically aimed at those dynamic environmental phenomena which impact on the Icelandic economy.

Williams, R. S., Jr.↗
NASA NTRS1973

Coastal and submarine features on MSS imagery of Southeastern Massachusetts: Comparison with conventional maps

Three ERTS-1, MSS images of southeastern Massachusetts, including Cape Cod Bay, Cape Cod, and Nantucket Sound, show a variety of dynamic geologic and hydrologic phenomena. Coastal features imaged include the coastline at different time in the tidal cycle, harbors, lakes and ponds, marshes (wetlands), and beach and dune areas; submarine features include tidal flats, shoals, dredged and natural channels, and bars. Comparison with conventional maps at 1:1,000,000 and 1:250,000 scales show many inaccuracies between the ERTS imagery and the two map scales. The ERTS-1 imagery can be used to increase the accuracy of these maps, portray additional environmental information, and provide the capability for frequent updating of maps at such scales. ERTS-1 imagery provides a very cost effective method for provision of certain types of environmental data for Cape Cod and environs.

Williams, R. S., Jr.↗
NASA NTRS1973

The cartographic application of ERTS/RBV imagery in polar regions

The author has identified the following significant results. Results of the SR-149 experiments demonstrated the feasibility of revising coastlines on maps of Antarctica, detected gross changes in the northern limits of the three largest ice shelves in the world, and led to the discovery of unmapped geographical features in Antarctica. Analyses of MSS imagery during the investigations show positive identification and obvious changes in size, shape, and position of such features as glaciers, ice tongues, ice shelves, and fast ice when compared to the existing USGS 1:250,000 scale maps. Investigations also pointed out that accurate and meaningful photoimage mosaics can be compiled at scales of 1:500,000 and 1:1,000,000 over the Polar Regions. With respect to the Antarctic region, many thousands of square miles can be image mapped for the very first time if cloud-free imagery becomes available and at a great reduction in cost of compilation. The international scientific community will benefit from such timely products. Current maps are a necessity for proper planning for field operations, especially over the treacherous terrain of the Antarctic.

Macdonald, W. R.↗
NASA NTRS1973

Evaluation of data utility for earth sciences from methodical point of view

The author has identified the following signficant results. A very distinct line representing the Ra-substage of the last deglaciation period is observable around the outer parts of the Oslo fjord. The moraine line is also traceable in some parts of the forest district on the Swedish side of the border forming part of the Central Swedish End Moraines. In the area of Lake Vanern to the southeast, the line is then again more distinct, partly due to the cultivation pattern. Outside the Central Swedish Moraine Line and nearer to the coast another not so distinct moraine line could be observed running NNW-SSE. This line crosses the coastline before reaching the Oslo fjord. Probably the moraine deposits on some outer islands in the fjord constitute part of this older moraine line. The study will be extended to districts of southern Sweden, where old moraine lines of the last deglaciation period are incompletely mapped.

Svensson, H.↗
NASA NTRS1973

Orbit analysis for coastal zone oceanography observations.

A study has been performed to define the orbital characteristics of a satellite dedicated to monitoring the coastal zones of the United States. The primary area of coverage is the east coast with secondary coverage of the west coast. Since no one orbital inclination fits both coasts, the inclination was determined by the east coast to be 63 deg. This inclination was found to give better coverage of the east coast than either its retrograde counterpart or a sun synchronous orbit. The two coasts require quite different orbits to maximize the coverage. The use of a small propulsive maneuver could be used to compromise the coverage between the two coastlines and change from one type orbit to the other.

Harrison, E. F.↗
NASA NTRS1973

Satellite geological and geophysical remote sensing of Iceland

The author has identified the following significant results. Under a binational, multidisciplinary experiment ERTS-1 imagery is being used to measure and map dynamic natural phenomena in Iceland. A few of the initial results from the project are: (1) a large variety of geological and volcanic features can be studied, particularly on imagery acquired at low sun angle ( 10 deg), which have not been previously recognized; (2) under optimum snow cover conditions, geothermal areas can be discerned by their snowmelt pattern or by warm spring discharge into frozen lakes; (3) a variety of map types at scale of 1:1,000,000 and 1:500,000, can be compiled, made more accurate, or updated (changes in coastline, glaciers, lakes, etc.); (4) the persistence of snow in the highland areas, during the summer months, has important ramifications to rangeland management; (5) false color composites (MSS) permitted the mapping of four types of vegetation; forested, reclaimed, cultivated areas and grasslands, and the mapping of the seasonal change of the vegetation, all of high value to rangeland management when complete, repetitive coverage of Iceland becomes a reality with an operational satellite; and (6) the volcanic eruption on Heimaey was recorded.

Williams, R. S., Jr.↗
NASA NTRS1973

On the use of drift bottle and seabed drifter data in coastal management

The use of drift bottle and seabed drifter information for use in coastal management is discussed. The drift bottle/seabed drifter portion of VIMS project MACONS (Mid Atlantic Continental Shelf) is described as an example of how a comprehensive survey using drift bottles and seabed drifters provides data useful for coastal management. The data from MACONS are analyzed to answer specific questions of interest to several different coastal managers: a manager siting a deep oil port, one siting a sewage outfall, a manager responsible for setting up emergency beach protection procedures before an accident occurs, and a manager responsible for the environmental quality of a particular small section of coastline.

Welch, C. S.↗
NASA NTRS1974

Satellite geological and geophysical remote sensing of Iceland

The author has identified the following significant results. ERTS-1 imagery provides sufficient resolution to discern two effects of geothermal activity at the Namafjall geothermal area: snowmelt anomalies and delineation of altered ground. The fallout pattern of tephra from Hekla's 1970 volcanic eruption can be mapped where sufficient depth of deposition destroyed the vegetation. Lava flows from the volcanic eruptions at Askja and Hekla can be delineated. Low sun-angle imagery of snow-covered terrain has permitted the mapping of new structural and volcanic features beneath the icecaps. Coastline changes on the islands of Surtsey and Heimaey can be mapped. Variations of sediment plumes from glacial rivers on the south coast give a qualitative indication of seasonal changes in melting rates of glaciers. ERTS-1 imagery has been shown to be especially amenable to portrayal of changing glaciological phenomena: surging glaciers, collapse features in icecaps caused by subglacial volcanic (?) and geothermal activity and resulting jokulhlaups, and variations in size of glacier-margin lakes. A fifth vegetation class has now been added: lichen-covered bedrock. The high latitude permits more precise analysis of landforms, vegetation distribution, occurrence of snow cover, glaciers, and geologic structure.

Williams, R. S., Jr.↗
NASA NTRS1974

An investigation of environmental factors associated with the current and proposed jetty systems at Belle Pass, Louisiana

The history of the existing jetty system at Belle Pass was investigated to determine its past effect on the littoral currents and beach erosion. Present flow patterns and erosion rates were also studied, along with the prevailing recession rates of local beaches not influenced by the jetty system. Aerial photographs and maps were used in conjunction with periodic hydraulic measurements, ground observations, and physical measurements of beach erosion. A scale model was constructed to further the study of flow patterns and velocities. It is shown that the existing jetty has not adversely affected the coastline in the area; erosive processes have been retarded by the jetty and its companion groin. Future erosion patterns are predicted, and projected effects of the proposed jetty system are given.

Dantin, E. J.↗
NASA NTRS1974

Wave climate model of the Mid-Atlantic shelf and shoreline (Virginian Sea): Model development, shelf geomorphology, and preliminary results

A computerized wave climate model is developed that applies linear wave theory and shelf depth information to predict wave behavior as they pass over the continental shelf as well as the resulting wave energy distributions along the coastline. Reviewed are also the geomorphology of the Mid-Atlantic Continental Shelf, wave computations resulting from 122 wave input conditions, and a preliminary analysis of these data.

Goldsmith, V.↗
NASA NTRS1974

A general description of Loran-C: Present and potential applications

Loran-C is a low frequency (100 kHz) pulse navigation system. The pulse format and phase stability of the system are of paramount importance for both navigation and time synchronization using this system. Present Loran-C installations operated by the U. S. Coast Guard cover much of the northern hemisphere. A recent government-wide decision has declared that Loran-C will be the U. S. Coastal confluence navigation system for the immediate future. Therefore, Loran-C stations are presently being installed or planned to cover the entire U. S. coastline.

Doherty, R. H.↗
NASA NTRS1975

Application of remote sensors in coastal zone observations

A review of processes taking place along coastlines and their biological consideration led to the determination of the elements which are required in the study of coastal structures and which are needed for better utilization of the resources from the oceans. The processes considered include waves, currents, and their influence on the erosion of coastal structures. Biological considerations include coastal fisheries, estuaries, and tidal marshes. Various remote sensors were analyzed for the information which they can provide and sites were proposed where a general ocean-observation plan could be tested.

Caillat, J. M.↗
NASA NTRS1975

Video guidance, landing, and imaging systems

The adaptive potential of video guidance technology for earth orbital and interplanetary missions was explored. The application of video acquisition, pointing, tracking, and navigation technology was considered to three primary missions: planetary landing, earth resources satellite, and spacecraft rendezvous and docking. It was found that an imaging system can be mechanized to provide a spacecraft or satellite with a considerable amount of adaptability with respect to its environment. It also provides a level of autonomy essential to many future missions and enhances their data gathering ability. The feasibility of an autonomous video guidance system capable of observing a planetary surface during terminal descent and selecting the most acceptable landing site was successfully demonstrated in the laboratory. The techniques developed for acquisition, pointing, and tracking show promise for recognizing and tracking coastlines, rivers, and other constituents of interest. Routines were written and checked for rendezvous, docking, and station-keeping functions.

Schappell, R. T.↗
NASA NTRS1975

Mapping islands, reefs and shoals in the oceans surrounding Australia

The author has identified the following significant results. Comparisons of the imagery with aerial photography of areas of reefs and island and with 1:250,000 maps of coastlines indicate that the MSS imagery depicts detail to an extent which is satisfactory for 1:250,000 mapping. As the imagery does not have some of the disadvantages of aerial photography, the former should be valuable for mapping reefs, islands, and shoals. The water discoloration problem is significant as the discolored water appears to occur near shallow depths, so that confusion could arise through the misinterpretation of discolored water, when it exists, as shallow water.

Turner, L. G.↗