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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 343 records · Page 19
All sourcesNASA NTRSDOE OSTI
NASA NTRS1974

Application of ecological, geological and oceanographic ERTS-1 imagery to Delaware's coastal resources management

The author has identified the following significant results. Data from twelve successful ERTS-1 passes over Delaware Bay have been analyzed with special emphasis on coastal vegetation, land use, current circulation, water turbidity and pollution dispersion. Secchi depth, suspended sediment concentration and transmissivity as measured from helicopters and boats were correlated with ERTS-1 image radiance. Multispectral signatures of acid disposal plumes, sediment plumes and slick were investigated. Ten vegetative cover and water discrimination classes were selected for mapping: (1) forest-land; (2) Phragmites communis; (3) Spartina patens and Distichlis spicata; (4) Spartina alterniflora; (5) cropland; (6) plowed cropland; (7) sand and bare sandy soil; (8) bare mud; (9) deep water; and (10) sediment-laden and shallow water. Canonical analysis predicted good classification accuracies for most categories. The actual classification accuracies were very close to the predicted values with 8 of 10 categories classified with greater than 90% accuracy indicating that representative training sets had been selected.

Klemas, V.↗
NASA NTRS1974

Research and investigation of geology, mineral, and water resources of Maryland

The authors have identified the following significant results. Field work in Baltimore County revealed that the signature returns of serpentinitic and nonserpentinitic rocks correlates with the vegetation cover and land use pattern. In Maryland Piedmont, bedrock lithology and structure are enhanced only to the extent that land use is geologically dictated. Two prominent sets of linear features are detected on ERTS-1 imagery at N 45 deg E and N 20 deg E. Beaches of Chesapeake Bay are classified as broad and narrow beaches based on the width of the backshore zone. It is shown by comparing historical shorelines of Ocean City, from the inlet to the Maryland-Delaware line that reversal zones of erosion and accretion occur at different locations for different periods. High reflectance levels (high marsh-high topographic areas) for the lower Eastern Shore are found to be distributed as two distinct trending linear ridge systems. Observations of MSS band 5 dated 9 April 1974 exhibited an unique sedimentation pattern for Chesapeake Bay. Following a 1.5 inch rainfall, heavy concentration of suspended sediments is observed on the imagery, particularly in the area of the turbidity maximum.

Weaver, K. N.↗
NASA NTRS1975

Oil-pollution detection and monitoring from space using ERTS-1

The author has identified the following significant results. Three reported spills were investigated using four digital computer, compatible techniques on ERTS - 1 data. A spill on the Atlantic Ocean (off Virginia) was studied to develop spectral signatures. Another spill, in Oakland Bay, was studied by ratioing spectral channels (to try to eliminate turbidity effects) and by summing different spectral channels to look for anomolus values caused by oil. The final spill, off Southern California, was investigated by looking for anomolus values in each channel separately. Results indicate that any of these methods might be usable if the spill is large enough to be seen by satellite, if the spill occurs more than a few kilometers off shore, and if the sky and water are relatively clear. In the case of the Atlantic spill, identification of material was not possible; and in the other two cases, the spills could not be detected at all. ERTS-1 was not considered feasible for this type of work because of its 18 day overpass frequency, the few spectral channels, the extended bandwidths, and the long, information retrieval time.

Horvath, R.↗
NASA NTRS1975

Requirements for airborne laser systems used in coastal studies

Requirements for airborne laser systems are considered for the following applications: (1) photo-optical determination of shallow water wave spectra; (2) bathymetry in highly turbid waters; (3) chlorophyll concentration monitoring; and (4) oil dispersion mapping.

Klemas, V.↗
NASA NTRS1975

Recent advances in the applications of pulsed lasers in the hydrosphere

Laboratory and field measurements have been performed on the transmission/scattering characteristics of a pulsed neon laser as a function of water turbidity. These results have been used to establish the criteria for an airborne laser bathymetry system. Extensive measurements have been made of laser induced fluorescence using a pulsed tunable dye laser. Feasibility has been demonstrated for remote detection and possible identification of various types of algae and oils. Similar measurements made on a wide variety of organic dyes have shown this technique to have applications in remote measurements of subsurface currents, temperature and salinity.

Hickman, G. D.↗
NASA NTRS1975

Processing of combined domestic bath and laundry waste waters for reuse as commode flushing water

An experimental investigation of processes and system configurations for reclaiming combined bath and laundry waste waters for reuse as commode flush water was conducted. A 90-min recycle flow was effective in removing particulates and in improving other physical characteristics to the extent that the filtered water was subjectively acceptable for reuse. The addition of a charcoal filter resulted in noticeable improvements in color, turbidity, and suds elimination. Heating and chlorination of the waste waters were investigated for reducing total organism counts and eliminating coliform organisms. A temperature of 335.9 K (145 F) for 30 min and chlorine concentrations of 20 mg/l in the collection tank followed by 10 mg/l in the storage tank were determined to be adequate for this purpose. Water volume relationships and energy-use rates for the waste water reuse systems are also discussed.

Hypes, W. D.↗
NASA NTRS1974

Coastal and estuarine studies with ERTS-1 and Skylab

Coastal vegetation, land use, current circulation, water turbidity, and ocean waste dispersion were studied by interpreting ERTS-1 and Skylab imagery with the help of ground truth collected during overpasses. Based on high-contrast targets such as piers and roads, the ERTS-1 multispectral scanner was found to have a resolution of 70-100 m, Skylab's S190A cameras about 20-40 m, and its S190B camera about 10-20 m. Important coastal land-use details can be more readily mapped using Skylab's imagery. On the other hand, the regular 18-day cycle of ERTS-1 allows observation of important man-made and natural changes, and facilitates collection of ground truth.

Klemas, V.↗
NASA NTRS1974

The economic impact of remote sensing data as the source of nonpoint pollution monitoring and control

Nonpoint pollution of streams with sediment as a result of runoff from alternative uses of land has become a socially unacceptable product of economic activity. This report describes a research approach to economically achieve correction of the nonpoint pollution problem. The research approach integrates the economic model with those data which may be obtainable from remotely sensed sources. The economic problem involves measurement of the direct benefits and costs associated with the changes in land management activities necessary to reduce the level of nonpoint pollution. Remotely sensed data from ERTS-1 may provide some of the information required for the economic model which indicates efficient solutions to the nonpoint pollution problem. Three classes of data (i.e., soil categories, vegetative cover, and water turbidity) have the potential to be measured by ERTS-1 systems. There is substantial research which indicates the ability of ERTS-1 to measure these classes of data under selected conditions.

Miller, W. L.↗
NASA NTRS1974

Preliminary results of fisheries investigation associated with Skylab-3

The purpose of the 15-month investigation now in the analysis phase is to establish the feasibility of utilizing remotely sensed data acquired from aircraft and satellite platforms to provide information concerning the distribution and abundance of oceanic gamefish. Data from the test area, jointly acquired by private and professional fishermen and NASA and NOAA/NMFS elements, in the northeastern Gulf of Mexico has made possible the identification of significant environmental parameters for white marlin. Predictive models based on catch data and surface truth information have been developed and have demonstrated potential for reducing search significantly by identifying areas which have a high probability of being productive. Three of the parameters utilized by the model, chlorophyll-a, sea surface temperature and turbidity have been inferred from aircraft sensor data.

Savastano, K.↗
NASA NTRS1974

Computer derived coastal water classifications via spectral signatures

In April 1973, the National Environmental Satellite Service conducted a remote sensing investigation within the coastal waters of the New York Bight. Remote sensor records acquired from the ERTS-1 Multispectral Scanner and the Bendix 24 Channel Multispectral Scanner records flown on the NASA C-130 were used for water mass classification. Computer-derived classifications are discussed and compared. Such features as the Hudson River's turbid discharge plumes, acid waste and shelf water are examined in terms of their distribution of suspended particulates (2-203 microns), transmissivity, diffuse attenuation, incident and returned spectral irradiances. The characteristics of these features and their relationship to the computer derived classifications are presented and discussed with respect to radiative transfer theory.

Clark, D. K.↗
NASA NTRS1975

Computed atmospheric corrections for satellite data

The corrections are presented for the visible and near infrared spectrum. The specifications of earth-atmosphere models are given. Herman's and Dave's methods of computing the four Stokes parameters are presented. The relative differences between the two sets of values are one percent. The absolute accuracy of the computations can be established only by comparisons with measured data. Suitable observations do not yet exist. Nevertheless, comparisons are made between computed and aircraft and satellite measured radiances. Particulates are the principal atmospheric variable in the window bands. They have a large effect on the radiances when the surface reflectivity is low. When the surface reflectivity exceeds 0.1, only absorbing particulates have a large effect on the reflectivity, unless the atmospheric turbidity is high. The ranges of the Multispectral Scanner responses to atmospheric effects are computed.

Fraser, R. S.↗
NASA NTRS1974

Satellite detection of air pollutants

NASA's ERTS-1 satellite, with its high resolution and multispectral capabilities, has been found useful in the detection and analysis of smoke from large point sources (power plants, steel mills, etc.), and widespread atmospheric turbidity associated with atmospheric stagnations. Smoke plumes from the Chicago-Northern Indiana industrial complex have been tracked over Lake Michigan for over 100 km. Experience has shown that smoke plumes are relatively easy to detect over water (in the 0.6-0.7 micrometer band) but much more difficult over land surfaces. Pattern recognition techniques (cluster analysis) were applied to the digital ERTS data, and it was found that the smoke plumes indeed had a unique spectral signature. Studies are currently underway to use measured plume geometries to obtain quantitative estimates of diffusion over water surfaces.

Lyons, W. A.↗
NASA NTRS1975

Interpretation of the variation of polarization over the disk of Venus

The polarization of reflected sunlight is computed for model atmospheres of Venus as a function of location on the apparent planetary disk. The calculations are for both homogeneous and layered models, as required to investigate the vertical distribution of particles. The results are compared with available observations. It is shown that the Rayleigh scattering observed in the polarization of Venus originates primarily from within the visible clouds, rather than from above the clouds. The visible 'clouds' are actually a very diffuse hazy region, and this visible-cloud layer extends at least up to the level where the pressure is of the order of 10 mb. The results indicate that the atmosphere behaves more nearly as the so-called 'homogeneous model' than as the 'reflecting-layer model'. However, there is some indication in the data that the turbidity increases with depth into the atmosphere. This conclusion receives stronger support from a comparison of particle number densities obtained from the polarization data with the number densities obtained from other observations which refer on the average to higher and lower levels in the atmosphere.

Kawabata, K.↗
NASA NTRS1974

The ERTS-1 investigation (ER-600). Volume 6: ERTS-1 signature extension analysis, July 1972 - June 1973

Feature classification, spatially and temporally, was extended over the Houston test site area. The Earth Resources Technology Satellite (ERTS-1) multispectral scanner data from August, September, and October 1972, of five widely separated lakes were used as statistical training fields and test sites. Short term temporal (same day to 36 days) and moderately long term spatial (within and between three ERTS multispectral scanner frames) signature extensions have been verified with respect to large relatively homogeneous features. The most significant feature dependent variable affecting spatial and short term extension was water turbidity. Long term signature extension will require a model to compensate or modify the ERTS-1 multispectral scanner data for significant sun angle changes. The presence of atmospheric haze changed the absolute signature but always by approximately the same amount so that the measured water signature was always the same. The normally occurring variations in atmospheric haze conditions had no major effect on the water signatures in this study.

Erb, R. B.↗
NASA NTRS1975

A Cost-effective Satellite-aircraft-drogue Approach for Studying Estuarine Circulation and Shelf Waste Dispersion

The author has identified the following significant results. Satellites, such as ERTS-1, can be used to obtain a synoptic view of current circulation over large coastal areas. Since in turbid coastal regions suspended sediment acts as a natural tracer, cost is minimized by eliminating the need for expensive injections of large volumes of dye such as Rhodamine-B. One of the principal shortcomings of satellite imaging of coastal currents was its inability to determine current magnitude and to penetrate beyond the upper few meters of the water column. These objections were overcome by complementing satellite observations with drogues tracking currents at various selected depths. By combining the satellite's wide coverage with aircraft or shore stations capable of tracking expendable drogues, a cost effective, integrated system was devised for monitoring currents over large areas, various depths, and under severe environmental conditions.

Klemas, V.↗
NASA NTRS1975

The use of LANDSAT-1 imagery for water quality studies in southern Scandinavia

The possibilities of using LANDSAT-1 images for environmental studies, with special references to water quality studies, were investigated by selecting test areas in southern Scandinavia. The MSS images of different bands are compared under the magnification of an Interpretoscope and densitometric analyses are performed in a Schnell-photometer. The possibility of tracing pollution plumes is studied in the Oresund outside Copenhagen. The effect of different sewers and the circulation of the polluted water is analyzed in various situations. The variation in reflectivity of a great number of lakes in South and Middle Sweden is studied by means of densitometric analyses and significant regional differences are found. The correlation with in situ measurements of water quality (turbidity and secchi disc transparency) of the sampled lakes (made by the National Swedish Environment Protection Board) is fairly good.

Hellden, U.↗
NASA NTRS1975

The feasibility of utilizing remotely sensed data to assess and monitor oceanic gamefish

An investigation was conducted to establish the feasibility of utilizing remotely sensed data acquired from aircraft and satellite platforms to provide information concerning the distribution and abundance of oceanic gamefish. The data from the test area was jointly acquired by NASA, the Navy, the Air Force and NOAA/NMFS elements and private and professional fishermen in the northeastern Gulf of Mexico. The data collected has made it possible to identify fisheries significant environmental parameters for white marlin. Prediction models, based on catch data and surface truth information, were developed and demonstrated a potential for significantly reducing search by identifying areas that have a high probability of productivity. Three of the parameters utilized by the models, chlorophyll-a, sea surface temperature, and turbidity were inferred from aircraft sensor data and were tested. Effective use of Skylab data was inhibited by cloud cover and delayed delivery. Initial efforts toward establishing the feasibility of utilizing remotely sensed data to assess and monitor the distribution of oceanic gamefish has successfully identified fisheries significant oceanographic parameters and demonstrated the capability of remotely measuring most of the parameters.

Savastano, K. J.↗