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At least 271 records · Page 15

Remote Sensing of Snow Fields from Earth Satellites

Considerable effort has gone into snow line delineation using available satellite data. Furthermore, increasing emphasis is being put on automated extraction of such information and generation of a useable product for hydrologists. Implications are clear that the impact from future satellite and sensors systems will create an increased demand for computer processing before the data can be used by the hydrologist. If the coarse-resolution, broad spectral band data available from current satellites already create a demand by hydrologists for computer processing of the data, it is obvious there will be an even greater demand for computer analysis and evaluation when the future ERTS data become available.

Baker, D. R.↗

Application of multispectral remote sensing to soil survey research in Indiana

Computer-implemented mappings based on spectral properties of bare soil surfaces were compared with mapping units of interest to soil surveyors. Some soil types could be differentiated by their spectral properties. In other cases, soils with similar surface colors and textures could not be distinguished spectrally. The spectral maps seemed useful for delineating boundaries between soils in many cases.

Zachary, A. L.↗

Foundations for a theory of gravitation theories

A foundation is laid for future analyses of gravitation theories. This foundation is applicable to any theory formulated in terms of geometric objects defined on a 4-dimensional spacetime manifold. The foundation consists of (1) a glossary of fundamental concepts; (2) a theorem that delineates the overlap between Lagrangian-based theories and metric theories; (3) a conjecture (due to Schiff) that the Weak Equivalence Principle implies the Einstein Equivalence Principle; and (4) a plausibility argument supporting this conjecture for the special case of relativistic, Lagrangian-based theories.

Thorne, K. S.↗

Monitoring of Air Pollution by Satellites (MAPS), phase 1

Results are reported upon which the design of a satellite remote gas filter correlation (RGFC) instrument can be based. Although a final decision about the feasibility of measuring some of the pollutants with the required accuracy is still outstanding and subject to further theoretical and experimental verifications, viable concepts are presented which permit the initiation of the design phase. The pollutants which are of concern in the troposphere and stratosphere were selected. The infrared bands of these pollutants were identified, together with the bands of interfering gases, and the line parameters of the pollutants as well as interfering gases were generated through a computer program. Radiative transfer calculations (line-by-line) were made to establish the radiation levels at the top of the atmosphere and the signal levels at the detector of the RGFC instrument. Based upon these results the channels for the RGFC were selected. Finally, the problem areas, which need further investigations, were delineated and the supporting data requirements were established.

Ludwig, C. B.↗

Chemical nonequilibrium effects on the inviscid flow in the windward plane of symmetry of two simplified shuttle configurations

A theoretical study was made to delineate the effects of thermochemical nonequilibrium in the inviscid flow field of a representative space shuttle orbiter configuration. The study was based on experimental pressure data which was used as an input to a stream tube computer program. The pressure data from two configurations are tabulated. Calculations were restricted to the windward plane of symmetry and the calculations covered an altitude range from 200,000 to 250,000 feet at velocities of 16,000 to 24,000 feet per second respectively. Angles of attack of 20 and 40 degrees were included. The calculations show that the nonequilibrium effects are confined largely to the entropy layer expect at the highest altitude, where significant nonequilibrium effects are observed in the entire inviscid flow field.

Lordi, J. A.↗

Evaluation of feasibility of mapping seismically active faults in Alaska

The author has identified the following significant results. ERTS-1 imagery is proving to be exceptionally useful in delineating structural features in Alaska which have never been recognized on the ground. Previously unmapped features such as seismically active faults and major structural lineaments are especially evident. Among the more significant results of this investigation is the discovery of an active strand of the Denali fault. The new fault has a history of scattered activity and was the scene of a magnitude 4.8 earthquake on October 1, 1972. Of greater significance is the disclosure of a large scale conjugate fracture system north of the Alaska Range. This fracture system appears to result from compressive stress radiating outward from around Mt. McKinley. One member of the system was the scene of a magnitude 6.5 earthquake in 1968. The potential value of ERTS-1 imagery to land use planning is reflected in the fact that this earthquake occurred within 10 km of the site which was proposed for the Rampart Dam, and the fault on which it occurred passes very near the proposed site for the bridge and oil pipeline crossing of the Yukon River.

Gedney, L. D.↗

Monitoring the vernal advancement and retrogradation (green wave effect) of natural vegetation

The author has identified the following significant results. Preliminary evaluation of autumnal phase ground truth data suggests that the sampling procedures at the Great Plains Corridor network test sites are adequate to show relatively small temporal changes in above-ground vegetation biomass and vegetation condition. Vegetation changes measured August through December, reflect grazing intensity and environmental conditions at the test sites. Preliminary analysis of black and white imagery suggests that detail in vegetation patterns is much greater than originally anticipated. A first look analysis of single band imagery and digital data at two locations shows that woodland, grassland, and cropland areas are easily delineated. Computer derived grey-scale maps from MSS digital data were shown to be useful in identifying the location of small fields and features of the natural and cultivated lands. Single band imagery and digital data are believed to have important application for synoptic land use mapping and inventory. Initial ratio analysis, using band 5 and 7 data, suggests the applicability in the greenness of a vegetative scene.

Rouse, J. W., Jr.↗

Geology of Utah and Nevada by ERTS imagery

The author has identified the following significant results. Two ancient watercourses have been observed on ERTS-1 imagery. These lie in the Waterpocket Fold area, north of the Marble Canyon section of the Colorado River, in Arizona and Utah. A third old watercourse of interest is an ancient canyon of the Colorado and is located on image no. 1156-17260. Image no. 1051-17414 contains some very useful information concerning the hydrology, sedimentology, and biology of Great Salt Lake and Bear Lake in Utah. In Great Salt Lake, there is a sharp line between the portion of the lake north of the railroad causeway and that south of the causeway. There is a marked difference in salinity across the causeway, and this is reflected in different algal species. On the same image, sediment plumes in Bear Lake clearly delineate the circulation pattern, and provide excellent indications of bottom contours over much of the area. Image no. 1051-17420 contains part of Great Salt Lake and all of Utah Lake. The latter displays a very interesting surface pattern which is probably due to an algal bloom which has been swirled into a spiral by the circulation of the lake.

Jensen, M. L.↗

Application of ERTS-1 data to the protection and management of New Jersey's coastal environment

The author has identified the following significant results. Photomaps, using MSS bands 5 and 7, have been prepared delineating the coastal zone as described in the Coastal Area Facility Review Act before the State Legislature. An upper wetlands boundary overlay has been prepared at 1:500,000 scale. The movement and dispersion of wastes in the New York Bight area are being plotted with each orbit. The possible impact of these wastes on the New Jersey shoreline is being quantified.

Yunghans, R. S.↗

Evaluation of ERTS-1 imagery for mapping Quaternary deposits and landforms in the Great Plains and Midwest

The author has identified the following significant results. The main landform associations and larger landforms are readily identifiable on the better images and commonly the gross associations of surficial Quaternary deposits also can be differentiated, primarily by information on landforms and soils. Maps showing the Quaternary geologic-terrain units that can be differentiated from the ERTS-1 images are being prepared for 20-odd potential study areas in Illinois, Iowa, Missouri, Kansas, Nebraska, and South Dakota. Among the more distinct features are the major moraines and outwash channels of the last (Wisconsin) glaciation. Analysis of dissection/drainage patterns from the synoptic imagery is proving useful for detecting anomalies that may be caused by stream diversions and moraines of pre-Wisconsin glaciations, by variable loess deposition, by tectonism, and other factors. Numerous abandoned river valleys have been mapped. Trend-lines of several known pre-Wisconsin moraine systems have been identified in Iowa, Nebraska, and Kansas, and also several similar trend-lines, that may indicate previously unknown moraine systems of middle and possibly early Pleistocene age, have been found in Iowa and Missouri. The area inundated by a major flood in southwestern Iowa also has been delineated from ERTS-1 imagery.

Morrison, R. B.↗

Reflectance measurements for the detection and mapping of soil limitations

During 1971 and 1972 research was conducted on two fallow fields in the proposed Oahe Irrigation Project to investigate the relationship between the tonal variations observed on aerial photographs and the principal soil limitations of the area. A grid sampling procedure was used to collected detailed field data during the 1972 growing season. The field data was compared to imagery collected on May 14, 1971 at 3050 meters altitude. The imagery and field data were initially evaluated by a visual analysis. Correlation and regression analysis revealed a highly significant correlation and regression analysis revealed a highly significant correlation between the digitized color infrared film data and soil properties such as organic matter content, color, depth to carbonates, bulk density and reflectivity. Computer classification of the multiemulsion film data resulted in maps delineating the areas containing claypan and erosion limitations. Reflectance data from the red spectral band provided the best results.

Benson, L. A.↗

The development of hurricane Inez, 1966, as shown by satellite nighttime radiometric and daytime television coverage

A complete documentation of Numbus 2 High Resolution infrared Radiometer data and ESSA-1 and 3 television photographs is presented for the life-time of Hurricane Inez, 1966. Ten computer produced radiation charts were analyzed in order to delineate the three dimensional cloud structure during the formative, mature and dissipating stages of this tropical cyclone. Time sections were drawn throughout the storm's life cycle to relate the warm core development and upper level outflow of the storm with their respective cloud canopies, as shown by the radiation data. Aerial reconnaissance weather reports, radar photographs and conventional weather analyses were used to complement the satellite data. A computer program was utilized to accept Nimbus 2 HRIR equivalent blackbody temperatures within historical maximum and minimum sea surface temperature limits over the tropical Atlantic Ocean.

Allison, L. J.↗

A high speed sequential decoder

The performance and theory of operation for the High Speed Hard Decision Sequential Decoder are delineated. The decoder is a forward error correction system which is capable of accepting data from binary-phase-shift-keyed and quadriphase-shift-keyed modems at input data rates up to 30 megabits per second. Test results show that the decoder is capable of maintaining a composite error rate of 0.00001 at an input E sub b/N sub o of 5.6 db. This performance has been obtained with minimum circuit complexity.

Lum, H., Jr.↗

Break-up characteristics of Chena River Basin

The author has identified the following significant results. Utilization of the color additive viewer was made to delineate snow boundary conditions from imagery taken during the fall snow accumulation period. By using filters that falsely colored the vegetation red, the snow cover appeared white.

Carlson, R. F.↗

Analysis of ERTS-1 imagery of Wyoming and its application to evaluation of Wyoming's natural resources

The author has identified the following significant results. The Wyoming investigation has progressed according to schedule during the Jan. - Feb., 1973 report period. A map of the maximum extent of Pleistocene glaciation was compiled for northwest Wyoming from interpretations of glacial features seen on ERTS-1 imagery. Using isodensitometry as a tool for image enhancement, techniques were developed which allowed accurate delineation of small urban areas and provided distinction of broad classifications within these small urban centers.

Marrs, R. W.↗

Use of satellite imagery for wildland resource evaluation in the Great Basin

The author has identified the following significant results. Upon receipt of ERTS-1 imagery, scale and resolution determinations were made. It was found that the scale was quite close to the anticipated 1:1 million, and that each ERTS-1 frame had a coverage of approximately 12,500 square miles. A water body 275 feet across was identified on the MSS 7 band as a determination of maximum resolution. Large cities were easily distinguished on all bands. Paved highways and railroads were able to be identified when there was extreme contrast between these structures and surrounding areas. Landforms were identified on all bands, but band 5 proved superior. Vegetation of varying types was identified using band 7. Fields and agricultural areas were identified as was phreatophytic vegetation. Timber, pinyon-juniper, sagebrush, mountain brush, and annual grassland communities were identified on selected frames. Phenology comparisons of selected test sites were made using sequential U-2 imagery. It was found that gray scale and color IR changes relating to the phenology of certain annual grassland, mountain brush, and marsh communities could be identified. Water bodies were identified and delineated using band 7.

Tueller, P. T.↗

Remote sensing of permafrost and geological hazards in Alaska

The author has identified the following significant results. The study of the ERTS-1 imagery of Alaska indicates the following: that areas of different topographic expression affecting the distribution and character of permafrost can be distinguished clearly; that on the Arctic North Slope, regional differences in the distribution and character of permafrost-related oriented thaw lakes can be observed; that the distribution of certain types of geologic materials having a significant effect on the character of permafrost can be delineated on a regional scale; and that the resolution of the imagery is adequate to identify large scale geologic hazards such as landslides, glacier-dammed lakes, aufeis fields, etc. The information concerning the distribution and character of permafrost and geologic hazards to the gained in accomplishing the objectives of this project will be an invaluable aid in solving engineering-geologic and environmental problems related to route and site selection for structures such as roads, railroads, pipelines, and large installations; to distribution of natural construction materials; and to construction and maintenance.

Ferrians, O. J., Jr.↗

Definition of the Informational Requirements of Hydrologic Resource Managers

The objectives of the integrated study are; (1) to delinate the parameters involved in hydrologic systems; (2) to outline the conventional means used in acquiring information relative to those parameters; and (3) to consider the potential usefulness of modern remote sensing techniques for acquiring certain parts of this information.

Burgy, R. H.↗