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  • 1
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    Amsterdam ; New York : North-Holland Pub. Co
    Schlagwort(e): DDC 530.1 ; LC QC20 ; Mathematical physics ; Physics ; Quantum theory ; Relativity (Physics)
    ISBN: 9780444875853
    Sprache: Englisch
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  • 2
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    In:  CASI
    Publikationsdatum: 2009-11-16
    Beschreibung: Background information and exercises are provided to: (1) establish or expand understanding of the concepts, methods, and terminology of computer processing of image producing data; (2) develop insight into the advantages of computer based image processing compared with the photointerpretation approach for processing, classifying, interpreting, and applying remote sensing data; (3) foster a broad perspective on the principal of the main techniques for image enhancement, pattern recognition, and thematic classification; (4) appreciate the pros and cons of batch and interactive modes of image analysis; (5) examine and evaluate some specific computer generated products for subscenes in Pennsylvania and New Jersey; and (6) interrelate these particular examples of output with more theoretical explanations of computer processing strategies and procedures.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: The LANDSAT Tutorial Workbook; p 145-232
    Format: text
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  • 3
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    In:  CASI
    Publikationsdatum: 2006-04-06
    Beschreibung: Isolated knobs that are erosional remnants of central volcanoes or of folded rocks occur in several areas of the Altiplano are visible on both optical and images. The optically visible streaks occur in the immediate lee of the knobs, whereas the radar visible streaks occur in the zone downwind between the knobs. Aerial reconnaissance and field studies showed that the optically visible streaks consist of a series of small ( 100 m wide) barchan and barchanoid dunes, intradune sand sheets, and sand hummocks (large shrub coppice dunes) up to 15 m across and 5 m high. On LANDSAT images these features are poorly resolved but combine to form a bright streak. On the radar image, this area also appears brighter than the zone of the radar dark streak; evidently, the dunes and hummocks serve as radar reflectors. The radar dark streak consists of a relatively flat, smooth sand sheet which lacks organized aerolian bedforms, other than occasional ripples. Wind velocity profiles show a greater U value in the optically bright streak zone than in the radar dark streak.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: NASA. Washington Rept. of Planetary Geology Program, 1983; p 271-272
    Format: text
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  • 4
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    In:  CASI
    Publikationsdatum: 2006-04-06
    Beschreibung: The terrain analysis software package was restructured and documentation was added. A program was written to test Johnson Space Center's four band scatterometer data for spurious signals data. A catalog of terrain roughness statistics and calibrated four frequency multipolarization scatterometer data is being published to support the maintenance of Death Valley as a radar backscatter calibration test site for all future airborne and spacecraft missions. Test pits were dug through sand covered terrains in the Eastern Sahara to define the depth and character of subsurface interfaces responsible for either backscatter or specular response in SIR-A imagery. Blocky sandstone bedrock surfaces at about 1 m depth were responsible for the brightest SIR-A returns. Irregular very dense CaCO3 cemented sand interfaces were responsible for intermediate grey tones. Ancient river valleys had the weakest response. Reexamination of SEASAT l-band imagery of U.S. deserts continues.
    Schlagwort(e): COMMUNICATIONS AND RADAR
    Materialart: NASA. Washington Rept. of Planetary Geology Program, 1983; p 268-269
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  • 5
    Publikationsdatum: 2006-04-06
    Beschreibung: The diversity of proposed origins for large Martian outflow channels results from the differing interpretations given to the landforms associated with the outflow channels. In an attempt to help limit the possible mechanisms of channel erosion, detailed studies of three of the channel features were done; the streamlined islands, longitudinal grooves and scour marks. This examination involved a comparison of the martian streamlined islands with various streamlined landforms on Earth including those found in the Channel Scabland in large rivers, glacial drumlins, and desert yardangs. The comparisons included statistical analyses of the landform lengths versus widths and positions of maximum width, and an examination of the degree of shape agreement with the geometric lemniscate which was in turn demonstrated to correspond closely with true airfoil shapes. The analyses showed that the shapes of the martian islands correspond closely to the streamlined islands in rivers and the Channel Scabland land. Drumlins show a much smaller correlation. Erosional rock islands formed by glaciers are very much different in shape.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: NASA. Washington Rept. of Planetary Geol. Programs; p 200-202
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  • 6
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    In:  CASI
    Publikationsdatum: 2006-02-14
    Beschreibung: The new NASA Deep Space Network (DSN) 34-m-diameter azimuth-elevation (Az-El) antenna structure is an example of an essentially computer-automated design. In addition to pivotal comptuer Lagrange multiplier design optimization software, much of the associated pre- and post-processing was also performed by computer. The construction of one of these antennas at Goldstone, California, is well advanced and will be completed this summer. A second installation is in progress in Australia. Both atennas will be used primarily for spacecraft tracking and will operate in the 8.5-GHz, 3.5-cm (1.4-in.) wavelength microwave frequency.
    Schlagwort(e): COMMUNICATIONS AND RADAR
    Materialart: NASA. Langley Research Center Recent Experiences in Multidisciplinary Analysis and Optimization, Part 2; 16 p
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  • 7
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    In:  CASI
    Publikationsdatum: 2006-02-14
    Beschreibung: The physical characteristics of speech, the methods of speech masking measurement, and the effects of noise on speech communication are investigated. Topics include the speech signal and intelligibility, the effects of noise on intelligibility, the articulation index, and various devices for evaluating speech systems.
    Schlagwort(e): COMMUNICATIONS AND RADAR
    Materialart: Physiol., Psychol., and Social Effects of Noise; p 57-110
    Format: text
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  • 8
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    In:  CASI
    Publikationsdatum: 2006-04-16
    Beschreibung: Images characteristics of geographic regions other than the northeastern part of the United States are presented for interpretation. Pre- and post-eruption imagery of Mt. St. Helens volcano serves to demonstrate the advantages of thermal infrared sensing, and the potential for developing a timely, decision oriented thematic map to be used in solving drought-related problems in Upper Volta is examined to show the applicability of satellite remote sensing in all geographic areas.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: The LANDSAT Tutorial Workbook; p 455-475
    Format: text
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  • 9
    Publikationsdatum: 2006-04-12
    Beschreibung: The 1980 eruptions of Mount St. Helens in southeast Washington resulted in a pronounced effect on the surface and ground water resources of the state. In response to the volcanic activity, the U.S. Geological Survey intensified statewide surface and ground water sampling programs to determine the nature and magnitude of the volcanic-induced variations. Streams to the east of Mount St. Helens received the major ash fallout. Chemical effects were best noted in smaller streams sampled 60 to 70 miles northeast of Mount St. Helens. The chemical variations observed were pronounced but short lived. Sulfate and chloride increases in anionic composition were prevalent immediately following the eruption; however, the original bicarbonate predominance was again attained within several days. Suspended iron and aluminum concentrations were similarly elevated during the period of greatest ash deposition (highest turbidity); however, the dissolved concentrations remained relatively constant. Depressions of pH were minor and short lived. Streams draining to the south, tributaries to the Columbia river, showed little observable changes in water chemistry. Streams draining to the west (Toutle river and its tributaries) were compositionally affected by the various volcanic activities. Chloride and sulfate anion percentage exceeded the bicarbonate percentage up to one month following the eruption period. Streams and lakes sampled in the immediate vicinity of Mount St. Helens, in addition to trace metals, contained organic compounds derived from decomposing wood buried in the debris deposits. This organic material may constitute a significant source of organic compounds to surface and ground water for some time to come.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: NASA. Langley Research Center Atmospheric Effects and Potential Climatic Impact of the 1980 Eruptions of Mt. St. Helens; p 43-46
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  • 10
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    In:  CASI
    Publikationsdatum: 2006-04-16
    Beschreibung: The benefits-to-cost ratio of satellite remote sensing, both as a substitute for conventional methods of monitoring and assessing resources, and as a supplement to these methods is examined using a model which analyzes the cost of aerial photography versus satellite scanner for producing and interpreting an image of the Earth's surface sized to LANDSAT dimensions. Examples of cost savings are tabulated for ground surveys, aerial photos, and LANDSAT. Possible additional benefits from LANDSAT D are assessed. The way in which satellites fit into more comprehensive models for resources management is discussed. It is shown that remote sensing is but one essential component in a complex system that aggregates technical. Socioeconomics, political, cultural, and other factors in the human decision process.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: The LANDSAT Tutorial Workbook; p 389-407
    Format: text
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  • 11
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    In:  CASI
    Publikationsdatum: 2006-04-16
    Beschreibung: Computer processing facilitates extraction of information from every pixel by executing a variety of functional operations, called processed algorithms, in general or specialized routines. The best results are obtained when data from more than one multispectral band are used together. Multivariate tatistical analysis, computer tape characteristics, processing modes, and a choice of systems (batch or interactive) are discussed. The major operations in computer processing elaborated include: preprocessing, enhancement, effects of rationing, and classification. Techniques for multisource data correlation are considered with emphasis on geobased systems.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: The LANDSAT Tutorial Workbook; p 421-453
    Format: text
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  • 12
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    In:  CASI
    Publikationsdatum: 2006-04-16
    Beschreibung: Learning objectives include: (1) developing an understanding of the implications of the term "near surface observations"; (2) associating the appearance of large ground features as seen in satellite imagery with their appearance as seen from the ground; (3) grasping criteria and procedures for selecting training sites on the ground for use in supervised classification; (4) running through an example of training site selection; (5) becoming familiar with several methods of accuracy assessment; (6) becoming aware of the approach and value of making supporting measurements of the spectral and physical properties of materials on the ground and from aircraft; (7) taking note of the different types of instruments used in making specific ground measurements; and (8) appreciating the rationale underlying laboratory and field studies on or near the Earth's surface for the purpose of developing new sensor systems.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: The LANDSAT Tutorial Workbook; p 233-276
    Format: text
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  • 13
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    In:  CASI
    Publikationsdatum: 2006-04-16
    Beschreibung: Learning objectives include: (1) developing a facility for applying conventional techniques of photointerpretation to small scale (satellite) imager; (2) promoting the ability to locate, identify, and interpret small natural and man made surface features in a LANDSAT image; (3) using supporting imagery, such as aerial and space photography, to conduct specific applications analyses; (4) learning to apply change detection techniques to recognize and explain transient and temporal events in individual or seasonal imagery; (5) producing photointerpretation maps that define major surface units, themes, or classes; (6) classifying or analyzing a scene for specific discipline applications in geology, agriculture, forestry, hyrology, coastal wetlands, and environmental pollution; and (7) evaluating both advantages and shortcomings in relying on the photointerpretive approach (rather than computer based analytical approach) for extracting information from LANDSAT data.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: The LANDSAT Tutorial Workbook; p 101-143
    Format: text
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  • 14
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    In:  CASI
    Publikationsdatum: 2006-04-16
    Beschreibung: Activities are provided for: (1) developing insight into the way in which the LANDSAT MSS produces multispectral data; (2) promoting understanding of what a "pixel" means in a LANDSAT image and the implications of the term "mixed pixel"; (3) explaining the concept of spectral signatures; (4) deriving a simple signature for a class or feature by analysis: of the four band images; (5) understanding the production of false color composites; (6) appreciating the use of color additive techniques; (7) preparing Diazo images; and (8) making quick visual identifications of major land cover types by their characteristic gray tones or colors in LANDSAT images.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: The LANDSAT Tutorial Workbook; p 81-99
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  • 15
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    In:  CASI
    Publikationsdatum: 2006-04-16
    Beschreibung: Learning objectives of the activities provided include: (1) reading the annotation of a LANDSAT image; (2) becoming acquainted with the characteristics of 1:1,000,000 scale transparencies and prints of MSS images; (3) noting the general information visible in LANDSAT photo products; (4) observing changes of appearance of any ground feature or class in the black and white images made from the four MSS bands and the characteristic color of each class in color composites; (5) determining the degree to which a LANDSAT image meets map accuracy standards and can be fitted to map projections; (6) assessing the effects of LANDSAT enlargements and scale changes and of the limitations of satellite resolution relative to aerial photos; (7) observing the influence of time of acquisition (season) on a scene; (8) getting a feel for image quality as dependent on processing and photoreproduction; (9) appreciating the characteristics of the RBV and thermal band imagery obtained from LANDSAT-3; and (10) becoming familiar with certain attributes of adjacent LANDSAT images which permit them to be joined in mosaics and to be viewed in stereo.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: The LANDSAT Tutorial Workbook; p 39-80
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  • 16
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    In:  CASI
    Publikationsdatum: 2006-04-16
    Beschreibung: The primary LANDSAT mission and the system requirements are summarized and pertinent parameters of the spacecraft, its orbit, and payload are tabulated. The history acquisition to entry into the archives for storage and product generation and dissemination is recounted. The LANDSAT D data handling plan is discussed showing requirements for both the MSS CCT and the thematic mapper CCT.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: The LANDSAT Tutorial Workbook; p 409-419
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  • 17
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    In:  CASI
    Publikationsdatum: 2006-04-16
    Beschreibung: The term remote sensing is defined as well as ideas such as class, pattern, feature, pattern recognition, feature extraction, and theme. The electromagnetic spectrum is examined especially those wavelength regions available to remote sensing. Relevant energy and wave propagation laws are discussed and the characteristics of emitted and reflected radiation and their detection are investigated. The identification of classes by their spectral signatures, the multispectral approach, and the principal types of sensors and platforms used in remote sensing are also considered.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: The LANDSAT Tutorial Workbook; p 9-38
    Format: text
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  • 18
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    In:  CASI
    Publikationsdatum: 2006-06-04
    Beschreibung: Operation of the microwave instrument as a two frequency scatterometer, a synthetic aperture radar, and a passive microwave radiometer is planned. Operation of the instrument in each of its three modes is discussed and the antenna system described.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: NASA. Marshall Space Flight Center Spacelab Mission 1 Expt. Descriptions; 3 p
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  • 19
    Publikationsdatum: 2006-04-03
    Beschreibung: To establish confidence in its overall performance, credible information on the synthetic aperture radar antenna's mechanical properties in orbit must be obtained. However, the antenna's size, design, and operating environment make it difficult to simulate operating conditions under 1-g Earth conditions. The Space Technology Experiments Platform (STEP) offers a timely opportunity to mechanically qualify and characterize the antenna design in a representative environment. The proposed experimental configuration would employ a half-system of the full-scale RADARSAT antenna which would be mounted on the STEP platform in the orbiter cargo bay such that it could be deployed and retracted in orbit (as shown in this figure). The antenna would be subjected to typical environmental exposures while an array of targets and sensors on the antenna support structure and reflecting surface are observed and monitored. In particular, the typical environments would include deployment and retraction, dynamic response to vehicle thruster or base exciter inputs, and thermal soak and transient effects upon entering or exiting Earth eclipse. The proposed experiment would also provide generic information on the properties of large space structures in space and on techniques to obtain the desired information.
    Schlagwort(e): COMMUNICATIONS AND RADAR
    Materialart: NASA. Langley Research Center STEP Expt. Requirements; p 339-354
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  • 20
    Publikationsdatum: 2006-02-14
    Beschreibung: The internal response (electromagnetic fields and cable responses) of tactical shelters is addressed. Tactical shelters are usually well-shielded systems. Apart from penetrations by signal and power lines, the main leakage paths to the interior are via seams and the environment control unit (ECU) honeycomb filter. The time domain in three-dimensional finite-difference technique is employed to determine the external and internal coupling to a shelter excited by nuclear electromagnetic pulses (NEMP) and attached lightning. The responses of interest are the internal electromagnetic fields and the voltage, current, power, and energy coupled to internal cables. Leakage through the seams and ECU filter is accomplished by their transfer impedances which relate internal electric fields to external current densities. Transfer impedances which were experimentally measured are used in the analysis. The internal numerical results are favorably compared to actual shelter test data under simulated NEMP illumination.
    Schlagwort(e): COMMUNICATIONS AND RADAR
    Materialart: NASA. Langley Research Center Intern. Aerospace and Ground Conf. on Lightning and Static Elec.; 12 p
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  • 21
    Publikationsdatum: 2006-02-14
    Beschreibung: An approach to predict the susceptibility of digital systems to signal disturbances is described. Electrical disturbances on a digital system's input and output lines can be induced by activities and conditions including static electricity, lightning discharge, electromagnetic interference (EMI), and electromagnetic pulsation (EMP). The electrical signal disturbances employed for the susceptibility study were limited to nondestructive levels, i.e., the system does not sustain partial or total physical damage and reset and/or reload brings the system to an operational status. The front-end transition from the electrical disturbances to the equivalent digital signals was accomplished by computer-aided circuit analysis. The super-sceptre (system for circuit evaluation of transient radiation effects) programs was used. Gate models were developed according to manufacturers' performance specifications and parameters resulting from construction processes characteristic of the technology. Digital simulation at the gate and functional level was employed to determine the impact of the abnormal signals on system performance and to study the propagation characteristics of these signals through the system architecture. Example results are included for an Intel 8080 processor configuration.
    Schlagwort(e): COMMUNICATIONS AND RADAR
    Materialart: Intern. Aerospace and Ground Conf. on Lightning and Static Elec.; 14 p
    Format: text
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  • 22
    Publikationsdatum: 2006-02-14
    Beschreibung: A numerical modeling technique is utilized to investigate the response of a UH-60A helicopter to both lightning and nuclear electromagnetic pulses (NEMP). The analytical approach involves the three-dimensional time domain finite-difference solutions of Maxwell's equations. Both the external currents and charges as well as the internal electromagnetic fields and cable responses are computed. Results of the analysis indicate that, in general, the short circuit current on internal cables is larger for lightning, whereas the open-circuit voltages are slightly higher for NEMP. The lightning response is highly dependent upon the rise time of the injected current as was expected. The analysis shows that a coupling levels to cables in a helicopter are 20 to 30 dB larger than those observed in fixed-wing aircraft.
    Schlagwort(e): COMMUNICATIONS AND RADAR
    Materialart: NASA. Langley Research Center Intern. Aerospace and Ground Conf. on Lightning and Static Elec.; 7 p
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  • 23
    Publikationsdatum: 2006-02-14
    Beschreibung: Advanced composite aircraft designs include fault-tolerant computer-based digital control systems with thigh reliability requirements for adverse as well as optimum operating environments. Since aircraft penetrate intense electromagnetic fields during thunderstorms, onboard computer systems maya be subjected to field-induced transient voltages and currents resulting in functional error modes which are collectively referred to as digital system upset. A methodology was developed for assessing the upset susceptibility of a computer system onboard an aircraft flying through a lightning environment. Upset error modes in a general-purpose microprocessor were studied via tests which involved the random input of analog transients which model lightning-induced signals onto interface lines of an 8080-based microcomputer from which upset error data were recorded. The application of Markov modeling to upset susceptibility estimation is discussed and a stochastic model development.
    Schlagwort(e): COMMUNICATIONS AND RADAR
    Materialart: Intern. Aerospace and Ground Conf. on Lightning and Static Elec.; 12 p
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  • 24
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    In:  CASI
    Publikationsdatum: 2006-02-14
    Beschreibung: Prediction methods and related propagation results for the evaluation of Earth-space communication paths operating above 10 GHz are presented. Gaseous attenuation, rain, cloud, fog, sand, and dust attenuation, path diversity, signal fluctuations and low angle fading, depolarization effects, bandwidth coherence, and sky noise are considered.
    Schlagwort(e): COMMUNICATIONS AND RADAR
    Materialart: Propagation Effects Handbook for Satellite Systems Design; p 195-348
    Format: text
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  • 25
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    In:  CASI
    Publikationsdatum: 2006-02-14
    Beschreibung: The description and measurement of the macroscopic and microscopic characteristics of rain and rain systems are discussed. The statistical relationships of these characteristics and their effect on polarization and attenuation are considered. Macroscopic characteristics include the size, distribution, and movements of rain cells, the height of melting layers, and the presence of ice crystals. Microscopic characteristics include the size distribution, density, and oblateness of rain drops and ice crystals. The estimation of a major propagation effect, specific attenuation, is described.
    Schlagwort(e): COMMUNICATIONS AND RADAR
    Materialart: Propagation Effects Handbook for Satellite Systems Design; p 5-39
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  • 26
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    In:  CASI
    Publikationsdatum: 2006-02-14
    Beschreibung: Existing data bases accumulated as the result of experiments to gather propagation data on millimeter wave Earth-space links are described. The satellites used are described and results of the significant experiments conducted in the United States are summarized. The data bases consist primarily of cumulative attenuation statistics, though some depolarization measurements are included. Additional summaries of propagation data are cited.
    Schlagwort(e): COMMUNICATIONS AND RADAR
    Materialart: Its Propagation Effects Handbook for Satellite Systems Design; p 155-194
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  • 27
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    In:  CASI
    Publikationsdatum: 2006-02-14
    Beschreibung: In the Solar Power Satellite system, the antenna's misalignment will produce well defined grating lobes. These gratings lobe peaks occur every 440 km and are potentially hazardous to the environment. One way to suppress these peaks is to phase control every power module. The cost due to the increase in receiving electronics and processors, however, could prove to be prohibitive. A new design of the antenna involving the addition of two broad gaps, one along the x axis and another along the y axis is proposed. The gap distance is exactly one half of the distance between the center of two neighboring subarrays. Calculation of far field radiation patterns shows that the design reduces grating lobe peaks without sacrificing power in the main lobe.
    Schlagwort(e): COMMUNICATIONS AND RADAR
    Materialart: The 1981 NASA(ASEE Summer Fac. Fellowship Program; 14 p
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  • 28
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    In:  CASI
    Publikationsdatum: 2006-02-14
    Beschreibung: The key features of the Rice-Holmberg, Dutton-Dougherty, Global, Lin, and Piecewise Uniform Rain Rate models for estimation of cumulative attenuation statistics on Earth-space millimeter paths are summarized. The models provide either rain rate statistics or attenuation statistics, which can be related by use of the specific attenuation and the effective path length relation. The effective path length is defined. The advantages and disadvantages of each model for specific applications are discussed. The Global model is recommended as the design tool for predicting propagation effects in Earth-space communication systems.
    Schlagwort(e): COMMUNICATIONS AND RADAR
    Materialart: Propagation Effects Handbook for Satellite Systems Design; p 41-101
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  • 29
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    In:  CASI
    Publikationsdatum: 2006-02-14
    Beschreibung: The corresponding between a given propagation phenomenon and system performance is considered. Propagation data are related to system performance parameters, allowing the systems engineer to perform the analyses determining how well requirements are met by a given system design, and enabling the systems engineer to modify that design if necessary. The various ways of specifying performance criteria for different kinds of systems are discussed, and a general procedure for system design is presented and demonstrated.
    Schlagwort(e): COMMUNICATIONS AND RADAR
    Materialart: Propagation Effects Handbook for Satellite Systems Design; p 349-404
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  • 30
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    In:  CASI
    Publikationsdatum: 2006-02-14
    Beschreibung: Sources of depolarization effects on the propagation paths of orthogonally-polarized information channels are considered. The main sources of depolarization at millimeter wave frequencies are hydrometeor absorption and scattering in the troposphere. Terms are defined. Mathematical formulations for the effects of the propagation medium characteristics and antenna performance on signals in dual polarization Earth-space links are presented. Techniques for modeling rain and ice depolarization are discussed.
    Schlagwort(e): COMMUNICATIONS AND RADAR
    Materialart: Propagation Effects Handbook for Satellite Systems Design; p 103-154
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  • 31
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    In:  CASI
    Publikationsdatum: 2006-04-09
    Beschreibung: Real-time acousto-optic SAR processors are described and experimentally demonstrated. SAR imaging is performed in one of the architectures by applying the signal to an acousto-optic device and correlating it with chirp signals recorded on an optical transparency by time integration on a CCD detector. In a different implementation, the imaging is preformed by interfering the light beams diffracted from two separate acousto-optic devices, one modulated the radar signal and the second by the reference chirp waveform.
    Schlagwort(e): COMMUNICATIONS AND RADAR
    Materialart: NASA. Langley Research Center Opt. Inform. Process. for Aerospace Appl. 2; p 199-213
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  • 32
    Publikationsdatum: 2006-04-06
    Beschreibung: In order to understand better the polygenetic evolution of landforms on the martian surface, field studies were conducted in and around the Kharga Depression, Egypt. The Kharga region, on the eastern edge of Egypt's Western Desert, was subject to erosion under mostly hyperarid climatic conditions, punctuated by brief pluvial episodes of lesser aridity, since early Pleistocene time. The region contains numerous landforms analogous to features on the martian surface: yardangs carved in layered surficial deposits and in bedrock, invasive dune trains, wind-modified channels and interfluves, and depressions bounded by steep scarps. Like many of the topographic depresions on Mars, the Kharga Depression was invaded by crescentic dunes. In Egypt, stratigraphic relations between dunes, yardangs, mass-wasting debris, and wind-eroded flash-flood deposits record shifts in the relative effectiveness of wind, water, and mass-wasting processes as a function of climate change.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: NASA. Washington Rept. of Planetary Geology Program, 1983; p 225-227
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  • 33
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    In:  CASI
    Publikationsdatum: 2006-04-03
    Beschreibung: An antenna with rigid panels which can be measured under ground conditions, carried to space in a packaged condition, deployed into a form similar to the Earth-measured one, measured under space conditions, restowed, and brought back to Earth so that the original measurements can be verified is the type being proposed for this experiment. The antenna chosen will be measured under ground conditions, carried aloft, deployed into its antenna shape, lifted by the remote manipulator system to a position where it can be sighted by two astronauts at the two theodolites, and held there until the surface characterization can be completed. An alternate method would be to use photogrammetry and take pictures of the surface from the payload handling station. After the surface characterization is completed, the antenna will be folded and restowed into the Shuttle bay for return to Earth. The surface characterization will be repeated on Earth after its return for verification both of the original measurement taken on Earth and the measurement taken in space.
    Schlagwort(e): COMMUNICATIONS AND RADAR
    Materialart: STEP Expt. Requirements; p 333-338
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  • 34
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    In:  CASI
    Publikationsdatum: 2006-04-03
    Beschreibung: As an interim step in going to the 100-meter reflector that was evaluated, a 5-meter reflector is proposed to test the electrostatic concept under space conditions. Some of the issues which require the space environment for evaluation are the following questions: Can deployment of a box ring structure with a thin film reflector attached be manually deployed? In the absence of humidity, can a 0.3-mil aluminized Kapton film reflector be formed by the electrostatic process suitable for antenna applications? Can the photogrammetric process be used to evaluate the reflector surface with pictures taken from the payload handling station? Can the space charging effect be evaluated with the 5-meter reflector attached to the Shuttle? Does the outgassing of moisture from 0.3-mil Kapton film affect its reflector capability? A box ring truss support structure and an automatic sequence deployment system are discussed.
    Schlagwort(e): COMMUNICATIONS AND RADAR
    Materialart: STEP Expt. Requirements; p 325-331
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  • 35
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    Publikationsdatum: 2006-02-14
    Beschreibung: LANDSAT data acquired over an agricultural area along with ground enumeration of the same area are used to obtain crop acreage estimates which are better (as measured in terms of bias and variance) than can be obtained from either data source alone. Two basic approaches considered within the AgRISTARS program are a stratified crop acreage estimator and a regression estimator. A statement of the problem was mathematically formulated and some theorems were proved which relate to the variance of the two estimators. For a particular set of data, the regression and stratified estimators are compared in terms of certain easily computed parameters.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: Houston Univ. The 1981 NASA ASEE Summer Fac. Fellowship Program, Vol. 2; 17 p
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  • 36
    Publikationsdatum: 2006-04-06
    Beschreibung: Sand bars and islands within braided rivers have characteristic rhomboid or diamond shapes, often becoming very complex in form as the density of islands increases. Similar forms are observed in the martian outflow channels where the islands occur in groups. This contrasts with the more isolated martian islands which have airfoil shapes, as do isolated streamlined islands in rivers and in the Channeled Scabland. These observations indicate that the bar and island forms are controlled by the density of the islands, with increasing island interaction and flow modification as the density increases. As a continuation of previous flume experiments on the shapes of isolated islands, a new series of experiments investigate the modifications produced by a progressive increase in island density, finally leading to a true braided system.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: NASA. Washington Rept. of Planetary Geol. Programs; p 198-199
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  • 37
    Publikationsdatum: 2006-02-14
    Beschreibung: Kapton polyimide film was selected as the baseline material for the Grumman spce based radar (SBR) concept. To gain the requisite confidence for long-term service durability, it is desirable to subject material specimens as well as a portion of the SBR antenna directly to the combined space environment and compare property degradation to that caused by laboratory simulation. The overall objective of this program is to evauate the effect of the space environment on polymeric materials currently being considered for the Grumman SBR Phased-Array Antenna. Degradation mechanisms caused by thermal cycling, ultraviolet and charged-particle irradiation, applied load, and high-voltage plasma interaction will be evaluated. The experiment occupies a 6-in.-deep end corner tray located on the space end of the Long Duration Exposure Facility and consists of both passive and active parts. The passive part addresses the effect of environment and stress on the dimensional stability spliced and continuous Kapton, both plain and reinforced. The active part will study the interaction of high voltage and low-Earth-orbit plasma.
    Schlagwort(e): COMMUNICATIONS AND RADAR
    Materialart: NASA. Langley Research Center Long Duration Exposure Facility (LDEF); p 21-23
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  • 38
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    In:  CASI
    Publikationsdatum: 2006-04-16
    Beschreibung: The history of remote sensing is reviewed and the scope and versatility of the several remote sensing systems already in orbit are discussed, especially those with sensors operating in other EM spectral modes. The multisensor approach is examined by interrelating LANDSAT observations with data from other satellite systems. The basic principles and practices underlying the use of thermal infrared and radar sensors are explored and the types of observations and interpretations emanating from the Nimbus, Heat Capacity Mapping Mission, and SEASAT programs are examined. Approved or proposed Earth resources oriented missions for the 1980's previewed include LANDSAT D, Stereosat, Gravsat, the French satellite SPOT-1, and multimission modular spacecraft launched from space shuttle. The pushbroom imager, the linear array pushbroom radiometer, the multispectral linear array, and the operational LANDSAT observing system, to be designed the LANDSAT-E series are also envisioned for this decade.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: The LANDSAT Tutorial Workbook; p 327-387
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  • 39
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    In:  CASI
    Publikationsdatum: 2006-04-16
    Beschreibung: The use of computer aided classification of LANDSAT data in developing water quality plans for New Jersey watersheds is used to exemplify how a state natural resource management program benefits from satellite imagery. The transition of a research and development system into an operational remote sensing system to help decision makers is demonstrated. Nontechnial issues that can assist (or hinder) an agency in adopting a new technology are examined. The progress of LANDSAT use by state government from the earliest stage of curiosity through to incorporation in actual state planning methods is charted. Potential applications of LANDSAT data to real information needs and solutions to management problems are examined. The problems and mistakes that occurred in using LANDSAT data in the past are discussed as well as the ways by which these problems were overcome.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: The LANDSAT Tutorial Workbook; p 309-326
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  • 40
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    In:  CASI
    Publikationsdatum: 2006-04-16
    Beschreibung: Information and activities are provided to: (1) enhance the ability to distinguish between a Geographic Information System (GIS) and a data management system; (2) develop understanding of spatial data handling by conventional methods versus the automated approach; (3) promote awareness of GIS design and capabilities; (4) foster understanding of the concepts and problems of data base development and management; (5) facilitate recognition of how a computerized GIS can model conditions in the present "real world" to project conditions in the future; and (6) appreciate the utility of integrating LANDSAT and other remotely sensed data into the GIS.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: The LANDSAT Tutorial Workbook; p 277-308
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  • 41
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    Publikationsdatum: 2011-08-19
    Schlagwort(e): COMMUNICATIONS AND RADAR
    Materialart: NASA Technol. Appl. Team; p 20
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  • 42
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    Publikationsdatum: 2011-08-19
    Beschreibung: Sample images obtained with the Shuttle Imaging Radar A (SIR-A) are presented, along with design and performance features of the SIR-A, Seasat and Landsat images of the same scenes for comparison purposes. The SIR-A functions at the L-band 25 cm at a frequency of 1278 GHz with a spectral bandwidth of 6 MHz. The images were taken at an angle of 47 deg and furnished a resolution of 40 m from an altitude of 259 km. The images covered a ground swath 50 km wide. The images are provided to assist in the development of effective techniques for interpreting radar imagery. The SIR-A instrument is a precursor of another imaging device which will be flown around Venus. The images provided include sections of France, Sardinia and Algeria.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: Photo Interpretation (ISSN 0031-8523); 23; 4-17
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  • 43
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    Publikationsdatum: 2011-08-19
    Beschreibung: A new tropospheric mapping function is derived which is more accurate than previous mapping functions above elevations of 4 deg. The error due to the given analytic aproximation is estimated to be less than 0.2 percent for elevation angles larger than 6 deg (less than 0.4 cm at 6 deg). The mathematical expansion used in the derivation is valid for any laterally homogeneous atmospheric model of refractivity. The new mapping function, computer-generated ray tracing tables, and other mapping functions are compared.
    Schlagwort(e): COMMUNICATIONS AND RADAR
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  • 44
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    Publikationsdatum: 2011-08-18
    Beschreibung: Link margin estimates are calculated for 30/20 GHz satellite communication systems employing closely-spaced (4 to 100 km) 'dual diversity' switched ground sites. The link margin estimates are based on a new analysis in which the bivariate rain attenuation density function for two correlated ground sites is modelled by an exponential density function. The results of the exponential density function analysis enable derivation of a direct relation between rain margin estimates and probability of exceedance (link availability). Margins typically in the range 2 to 12 dB are calculated for various ground site separations and summarized for seven city locations and five satellite orbit positions over the U.S. The results can be easily extended to other EHF satellite frequencies and other locations.
    Schlagwort(e): COMMUNICATIONS AND RADAR
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  • 45
    Publikationsdatum: 2011-08-18
    Beschreibung: It is shown that, for convolutionally coded transmission over bandwidth-constrained channels, a mere reversal of the switching direction at the encoder output produces a change in the system bit error probability performance. This change is significant when the Viterbi demodulator/decoder is matched to the total channel memory and is more significant for linear channels than for nonlinear ones. The reversal of switching direction is a simple demonstration of the fact that the well-known optimum codes for the linear AGWN channel are no longer necessarily optimum for a bandwidth-constrained channel with or without the addition of channel nonlinearity. It is concluded that potentially significant performance improvement can be obtained by matching the encoder (through the appropriate choice of tap weights and modulo-2 summers) to the channel in addition to matching the demodulator/decoder to the channel for a given encoder.
    Schlagwort(e): COMMUNICATIONS AND RADAR
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  • 46
    Publikationsdatum: 2011-08-18
    Beschreibung: 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.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
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  • 47
    Publikationsdatum: 2011-08-18
    Beschreibung: Among the topics discussed are NASA's land remote sensing plans for the 1980s, the evolution of Landsat 4 and the performance of its sensors, the Landsat 4 thematic mapper image processing system radiometric and geometric characteristics, data quality, image data radiometric analysis and spectral/stratigraphic analysis, and thematic mapper agricultural, forest resource and geological applications. Also covered are geologic applications of side-looking airborne radar, digital image processing, the large format camera, the RADARSAT program, the SPOT 1 system's program status, distribution plans, and simulation program, Space Shuttle multispectral linear array studies of the optical and biological properties of terrestrial land cover, orbital surveys of solar-stimulated luminescence, the Space Shuttle imaging radar research facility, and Space Shuttle-based polar ice sounding altimetry.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
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  • 48
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    Publikationsdatum: 2011-08-18
    Beschreibung: Oil and gas deposits in the Alaskan Arctic are estimated to contain up to 40 percent of the remaining undiscovered crude oil and oil-equivalent natural gas within U.S. jurisdiction. Most (65 to 70 percent) of these estimated reserves are believed to occuur offshore beneath the shallow, ice-covered seas of the Alaskan continental shelf. Offshore recovery operations for such areas are far from routine, with the primary problems associated with the presence of ice. Some problems that must be resolved if efficient, cost-effective, environmentally safe, year-round offshore production is to be achieved include the accurate estimation of ice forces on offshore structures, the proper placement of pipelines beneath ice-produced gouges in the sea floor, and the cleanup of oil spills in pack ice areas.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: Science (ISSN 0036-8075); 225; 371-378
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  • 49
    Publikationsdatum: 2011-08-18
    Beschreibung: A multistage sampling procedure using image processing, geographical information systems, and analytical photogrammetry is presented which can be used to guide the collection of representative, high-resolution spectra and discrete reflectance targets for future satellite sensors. The procedure is general and can be adapted to characterize areas as small as minor watersheds and as large as multistate regions. Beginning with a user-determined study area, successive reductions in size and spectral variation are performed using image analysis techniques on data from the Multispectral Scanner, orbital and simulated Thematic Mapper, low altitude photography synchronized with the simulator, and associated digital data. An integrated image-based geographical information system supports processing requirements.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
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  • 50
    Publikationsdatum: 2011-08-18
    Beschreibung: The present investigation has the objective to develop a simple 'user's' model for simulating the measured radar backscattering coefficients from vegetation-covered fields in conjunction with the data obtained by Jackson et al. (1980, 1982). The theoretical work reported by Fung and Eom (1981) provides the basis for the model. Certain modifications are related to a consideration of the effect of a vegetation canopy. The first part of the model is concerned with a description of scatter from rough bare soil, while the second part takes into account the effect of a vegetation cover. It is shown that the measured angular distribution of the backscattering coefficient of vegetation-covered fields can be satisfactory reproduced by using the developed model.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: Remote Sensing of Environment (ISSN 0034-4257); 15; 119-133
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  • 51
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    Publikationsdatum: 2011-08-18
    Beschreibung: The atmospheric effect on the upward radiance of sunlight scattered from the earth-atmosphere system is strongly influenced by the contrasts between fields and their sizes. In this paper, the radiances above finite fields are computed to simulate radiances measured by a satellite. A simulation case including 11 agricultural fields and four natural fields (water, soil, savanah, and forest) is used to test the effect of field size, background reflectance, and optical thickness of the atmosphere on the classification accuracy. For a given atmospheric turbidity, the atmospheric effect on classification of surface features may be much stronger for nonuniform surfaces than for uniform surfaces. Therefore, the classification accuracy of agricultural fields and urban areas is dependent not only on the optical characteristics of the atmosphere, but also on the size of the surface elements to be classified and their contrasts. It is concluded that new atmospheric correction methods, which take into account the finite size of the fields, are needed.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: Remote Sensing of Environment (ISSN 0034-4257); 15; 95-118
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  • 52
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    Publikationsdatum: 2011-08-18
    Beschreibung: A goal of future synthetic aperture radar (SAR) system design is to yield the radiometrically accurate imagery necessary for use in classification problems. To accomplish this, a reliable calibration technique must be developed. Many such techniques have been proposed (e.g., Stiles and Holtzman, 1982); however, until now, none have been tested on spaceborne SAR digital data. In this paper, a method of significantly increasing the reproducibility of several independent Seasat SAR data sets of a test site using an automated correction procedure is described.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
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  • 53
    Publikationsdatum: 2011-08-18
    Beschreibung: The presence of positive serial correlation (autocorrelation) in remotely sensed data results in an underestimate of the variance-covariance matrix when calculated using contiguous pixels. This underestimate produces an inflation in F statistics. For a set of Thematic Mapper Simulator data (TMS), used to test the ability to discriminate a known geobotanical anomaly from its background, the inflation in F statistics related to serial correlation is between 7 and 70 times. This means that significance tests of means of the spectal bands initially appear to suggest that the anomalous site is very different in spectral reflectance and emittance from its background sites. However, this difference often disappears and is always dramatically reduced when compared to frequency distributions of test statistics produced by the comparison of simulated training sets possessing equal means, but which are composed of autocorrelated observations.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: International Journal of Remote Sensing (ISSN 0143-1161); 5; 315-332
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  • 54
    Publikationsdatum: 2011-08-18
    Beschreibung: The spectral and spatial requirements for remote sensing in the next decade are presented. The requirements presented were obtained through extensive literature research and discussions with leading members of the various remote sensing research communities. In the 0.35-2.5 micron region of the spectrum, numerous bands will be needed at bandwidths as narrow as 10-20 nanometers. There is also growing interest in the thermal infrared (8-14 microns). Spatial resolution (instantaneous field of view) of 5 to 10 meters will be of great benefit to many fields of remote sensing.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
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  • 55
    Publikationsdatum: 2011-08-18
    Beschreibung: The validity of using data from the Advanced Very High Resolution Radiometer (AVHRR) of the satellites NOAA-6 and NOAA-7 for land cover mapping is assessed by making comparisons with much higher resolution LANDSAT multi-spectral scanner (MSS) data. Near synchronous data for both systems are analysed for test sites in the Imperial Valley, California, the Nile Delta, and southern Italy. The results strongly indicate that despite the very coarse resolution of the AVHRR data compared with conventional MSS data they are sufficiently strongly correlated to suggest that the former have significant potential for land cover mapping, especially at small scales and for large areas. Hence the outstanding benefits of AVHRR data, namely their high temporal frequency, relative cheapness and low data volumes for image processing, may readily be taken advantage of for such tasks.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: International Journal of Remote Sensing (ISSN 0143-1161); 5; 497-504
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  • 56
    Publikationsdatum: 2011-08-18
    Beschreibung: The radiometric measurements over bare field and fields covered with grass, soybean, corn, and alfalfa were made with 1.4- and 5-GHz microwave radiometers during August-October 1978. The measured results are compared with radiative transfer theory treating the vegetated fields as a two-layer random medium. It is found that the presence of a vegetation cover generally gives a higher brightness temperature T sub B than that expected from a bare soil. The amount of this T sub B excess increases with increase in the vegetation biomass and in the frequency of the observed radiation. The results of radiative transfer calculations, which include a parameter characterizing ground surface roughness, generally match well with the experimental data.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: IEEE Transactions on Geoscience and Remote Sensing (ISSN 0196-2892); GE-22; 143-150
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  • 57
    Publikationsdatum: 2011-08-18
    Beschreibung: The technique for inverting a vegetation canopy reflectance model described earlier (Goel and Strebel, 1983) is investigated further. The novel concept of an 'angle transform' is introduced. This concept allows the formation of functions of reflectances at different view zenith and azimuth angles, which are either sensitive or insensitive to a certain agronomic parameter. A proper combination of these functions can allow determination of all the important agronomic and spectral parameters from measured canopy reflectance data. The technique is demonstrated using Suits' (1972) model for homogeneous canopies. It is shown that leaf area index, leaf reflectance and transmittance, and average leaf angle all can be determined from the canopy reflectance at a set of selected view zenith and azimuth angles. A sensitivity analysis of the calculated values to the errors in the data is also carried out. Guidelines are formulated for the number and types of observations required to obtain the values of a particular canopy variable to within a given degree of accuracy for a given level of error in the measurement of canopy reflectance.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: Remote Sensing of Environment (ISSN 0034-4257); 14; 77-111
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  • 58
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    Publikationsdatum: 2011-08-19
    Beschreibung: Minimum shift keying with Gaussian shaped transmit pulses is a strong candidate for a modulation technique that satisfies the stringent out-of-band radiated power requirements of the mobil radio application. Numerous studies and field experiments have been conducted by the Japanese on urban and suburban mobile radio channels with systems employing Gaussian minimum-shift keying (GMSK) transmission and differentially coherent reception. A comprehensive analytical treatment is presented of the performance of such systems emphasizing the important trade-offs among the various system design parameters such as transmit and receiver filter bandwidths and detection threshold level. It is shown that two-bit differential detection of GMSK is capable of offering far superior performance to the more conventional one-bit detection method both in the presence of an additive Gaussian noise background and Rician fading.
    Schlagwort(e): COMMUNICATIONS AND RADAR
    Materialart: IEEE Transactions on Vehicular Technology (ISSN 0018-9545); VT-33; 307-320
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  • 59
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    Publikationsdatum: 2011-08-19
    Beschreibung: Glacial landforms in the drumlin drift belt of Ireland and the Alaska Range can be identified and mapped from Seasat synthetic-aperture radar (SAR) images. Drumlins cover 60 percent of the Ireland scene. The width/length ratio of individual drumlins can be measured on the SAR images, allowing regional differences in drumlin shape to be mapped. This cannot be done with corresponding Landsat multispectral scanner (MSS) images because of lower spatial resolution and because of shadowing effects that vary seasonally. The Alaska scene shows the extent and nature of morphological features such as medial and lateral moraines, stagnant ice, and fluted ground moraine in glaciated valleys. Perception of these features on corresponding Landsat MSS images is limited by seasonal diffrences in solar illumination. Because SAR is not affected by such differences or by cloud cover, it is particularly well suited for monitoring glacial movement. The disadvantage of distorted high-relief features on Seasat SAR images can be reduced in future SAR systems by modifying the radar illumination geometry.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: Quaternary Research (ISSN 0033-5894); 22; 314-327
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  • 60
    Publikationsdatum: 2011-08-19
    Beschreibung: An evaluation of Thematic Mapper Simulator (TMS) data for the geobotanical discrimination of rock types based on vegetative cover characteristics is addressed in this research. A methodology for accomplishing this evaluation utilizing univariate and multivariate techniques is presented. TMS data acquired with a Daedalus DEI-1260 multispectral scanner were integrated with vegetation and geologic information for subsequent statistical analyses, which included a chi-square test, an analysis of variance, stepwise discriminant analysis, and Duncan's multiple range test. Results indicate that ultramafic rock types are spectrally separable from nonultramafics based on vegetative cover through the use of statistical analyses.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: IEEE Transactions on Geoscience and Remote Sensing (ISSN 0196-2892); GE-22; 525-530
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  • 61
    Publikationsdatum: 2011-08-19
    Beschreibung: An assessment is made of the information content of Thematic Mapper Simulator (TMS) data for the case of a forested region, in order to determine the sensitivity of such data to forest crown closure and tree size class. Principal components analysis and Monte Carlo simulation indicated that channels 4, 7, 5 and 3 were optimal for four-channel forest structure analysis. As the number of channels supplied to the Monte Carlo feature selection routine increased, classification accuracy increased. The greatest sensitivity to the forest structural parameters, which included succession within clearcuts as well as crown closure and size class, was obtained from the 7-channel TMS data.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: IEEE Transactions on Geoscience and Remote Sensing (ISSN 0196-2892); GE-22; 482-489
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  • 62
    Publikationsdatum: 2011-08-19
    Beschreibung: An historical account is given of the development of technology for the processing of satellite-acquired multispectral data aimed at the identification of the type, condition, and ontogenic stages of agricultural areas. During 1972 and 1973, research established the feasibility of automating digital classification for the processing of large volumes of Landsat MSS data. This capability was successfully demonstrated during the Large Area Crop Inventory Experiment, which estimated wheat crop production on a global basis. This achievement in turn led to the Agriculture and Resources Inventory Surveys Through Aerospace Remote Sensing, which investigated other portions of the electromagnetic spectrum and expanded the study of key commercial crops in important agricultural areas.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: IEEE Transactions on Geoscience and Remote Sensing (ISSN 0196-2892); GE-22; 473-482
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  • 63
    Publikationsdatum: 2011-08-19
    Beschreibung: The paper computes direct detection laser communications receiver performance when using avalanche photodiode (APD) detectors. The performances are compared in terms of bit error probability vs average signal required per bit when the transmitter uses either on-off keying (OOK) or low-order PPM formats. It is shown that QPPM requires 3 dB less signal than OOK, while BPPM requires the same or slightly more than OOK for the same performance. Optimum APD gain values range from 200 to 400. When using QPPM, k(eff) = 0.006, and optimum gain, 60 signal counts/bit are required at 500 Mbits/s for a 0.000001 bit error probability. It is concluded that QPPM may be an attractive signaling format for some fiber or free space laser communication applications.
    Schlagwort(e): COMMUNICATIONS AND RADAR
    Materialart: IEEE Transactions on Communications (ISSN 0090-6778); COM-32; 1140-114
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  • 64
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    Publikationsdatum: 2011-08-19
    Beschreibung: The present model for the temporal behavior of agricultural greenness is applied to the extraction of Landsat-derived profile features, distinguishing small from large grain crops. An additional feature derivable from the temporal behavior of the ratio of greenness to brightness is noted which aids in the separation of crops from other vegetation. A limited training set of 20 pure pixels/class, obtained from ground data, is subjected to the Ho-Kashyap (1965) linear classifier. The initial correct classification value for pure pixels of about 85 percent drops to 75 percent for all Landsat pixels.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: International Journal of Remote Sensing (ISSN 0143-1161); 5; 783-797
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  • 65
    Publikationsdatum: 2011-08-19
    Beschreibung: The utility of Landsat MSS classification methods in the case of small, highly urbanized hydrological basins containing complex land-use patterns is limited, and is plagued by misclassifications due to the spectral response similarity of many dissimilar surfaces. Landsat MSS data for the Conley Creek basin near Atlanta, Georgia, have been compared to thematic mapper simulator (TMS) data obtained on the same day by aircraft. The TMS data were able to alleviate many of the recurring patterns associated with MSS data, through bandwidth optimization, an increase of the number of spectral bands to seven, and an improvement of ground resolution to 30 m. The TMS is thereby able to detect small water bodies, powerline rights-of-way, and even individual buildings.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: International Journal of Remote Sensing (ISSN 0143-1161); 5; 761-770
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  • 66
    Publikationsdatum: 2011-08-19
    Beschreibung: An attempt has been made to relate hand-held radiometer measurements, and airborne multispectral scanner readings, with both different wheat stand densities and grain yield. Aircraft overflights were conducted during the tillering, stem extension and heading period stages of growth, while hand-held radiometer readings were taken throughout the growing season. The near-IR/red ratio was used in the analysis, which indicated that both the aircraft and the ground measurements made possible a differentiation and evaluation of wheat stand densities at an early enough growth stage to serve as the basis of management decisions. The aircraft data also corroborated the hand-held radiometer measurements with respect to yield prediction. Winterkill was readily evaluated.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: International Journal of Remote Sensing (ISSN 0143-1161); 5; 771-781
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  • 67
    Publikationsdatum: 2011-08-19
    Beschreibung: Ratios of intensities of near-infrared spectral bands, measured in reflectance, quantitatively predict the iron content of granitic rocks. Such data from the 1.60- and 1.05-micron bands of the Shuttle multispectral infrared radiometer have been used to study granitic rocks along orbits crossing Baja California, Mexico, and the Eastern Desert of Egypt. Both regions are arid and relatively to essentially free of vegetation, and there is no indication in the spectra that surface chemical alteration masks the true composition of the unweathered rock. Predicted values of iron are consistent with known compositional types of most of the rocks along the orbital paths. Results demonstrate that the near-infrared method used is a powerful technique to average the variability of these rocks on the scales of meters to kilometers.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: Journal of Geophysical Research (ISSN 0148-0227); 89; 9439-944
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  • 68
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    Publikationsdatum: 2011-08-18
    Beschreibung: Current development activities at JPL for ground mobile vehicle antennas to be used with the Land Mobile Satellite Service (LMSS) system are described. Both low gain and electronically steerable high gain type antennas are discussed in terms of their design concept and RF performance. For the low gain type, three classes of antennas are under various stages of development. These are the crossed-drooping dipole, quadrifilar helix, and microstrip patch designs. The antennas are intended to provide circularly-polarized radiation with a minimum of 3-dB gain in the angular region from 19 degrees to 60 deg from the horizon in elevation plane and with an omnidirectional pattern in azimuthal plane. For the electronically steerable high gain type, circularly-polarized microstrip patch phased arrays formed on a planar surface and on the surface of a truncated cone are under study. The arrays are intended to provide a minimum of 12 dB gain in the same angular region in elevation plane at all azimuthal angles. This coverage is accomplished by scanning the high gain pencil beam in both elevation and azimuthal directions. Both types of antennas are to transmit at 821-831 MHz band and to receive at 866-876 MHz band. They must be of low cost design and reasonably conformal to the vehicle.
    Schlagwort(e): COMMUNICATIONS AND RADAR
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  • 69
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    Publikationsdatum: 2011-08-18
    Beschreibung: The advanced communications technology satellite (ACTS) program of NASA is aimed at the development of high risk technologies that will enable exploiting higher frequency bands and techniques for improving frequency reuse. The technologies under development include multiple beam spacecraft antennas, on-board switching and processing, RF devices and components and advanced earth stations. The program focus is on the Ka-band (30/20 GHz) as the implementing frequency since it has five times the bandwidth of either the C- or Ku-bands. However, the technology being developed is applicable to other frequency bands as well and will support a wide range of future communications systems required by NASA, other Government agencies and the commercial sector. An overview is presented of an operational 30/20 GHz satellite system that may evolve. How the system addresses service requirements is discussed, and the technology required and being developed is considered. Previously announced in STAR as N83-11210
    Schlagwort(e): COMMUNICATIONS AND RADAR
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  • 70
    Publikationsdatum: 2011-08-18
    Beschreibung: The presence of positive serial correlation (autocorrelation) in remotely sensed data results in an underestimate of the variance-covariance matrix when calculated using contiguous pixels. This underestimate produces an inflation in F statistics. For a set of Thematic Mapper Simulator data (TMS), used to test the ability to discriminate a known geobotanical anomaly from its background, the inflation in F statistics related to serial correlation is between 7 and 70 times. This means that significance tests of means of the spectral bands initially appear to suggest that the anomalous site is very different in spectral reflectance and emittance from its background sites. However, this difference often disappears and is always dramatically reduced when compared to frequency distributions of test statistics produced by the comparison of simulated training sets possessing equal means, but which are composed of autocorrelated observations. Previously announced in STAR as N82-25602
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
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  • 71
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    Publikationsdatum: 2011-08-18
    Beschreibung: A complete automatic unsupervised classification approach has been developed to estimate the proportion of corn, soybeans, and other crops in a Landsat 5-by-6-nanometer segment. The technique involves extracting crop growth variables that are predictable from agromet models, it provides a signature extension not possible before. The technique has been applied in 3 years (1978-1980) for 56 segments and shows neither a year-to-year effect nor any geographic effect. The results to date are considered far better than those obtainable from any other currently available technique. Nontheless, the technique can be improved to reduce the bias.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
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  • 72
    Publikationsdatum: 2011-08-18
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
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  • 73
    Publikationsdatum: 2011-08-18
    Beschreibung: Since NASA's program of research concerning remote sensing was initiated in the 1960s, one of its major objectives has been to advance the state-of-the-art in machine processing of satellite acquired multispectral data. Possibilities have been studied regarding a use of these data to identify type, to monitor condition, and to estimate the ontogenetic stage of cultural vegetation. The present investigation provides a review of the state-of-the-art of the technology used to make remote sensing crop production estimates in foreign regions. Attention is given to Landsat data acquisition, aspects of registration and preprocessing, questions of data transformation, data modeling, proportion estimation, labeling, development stage models, crop condition models, and an outlook regarding future developments.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
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  • 74
    Publikationsdatum: 2011-08-18
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
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  • 75
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    Publikationsdatum: 2011-08-18
    Beschreibung: The improved spatial resolution of the new earth resources satellites will increase the need for effective utilization of spatial information in machine processing of remotely sensed data. One promising technique is scene segmentation by region growing. Region growing can use spatial information in two ways: only spatially adjacent regions merge together, and merging criteria can be based on region-wide spatial features. A simple region growing approach is described in which the similarity criterion is based on region mean and variance (a simple spatial feature). An effective way to implement region growing for remote sensing is as an iterative parallel process on a large parallel processor. A straightforward parallel pixel-based implementation of the algorithm is explored and its efficiency is compared with sequential pixel-based, sequential region-based, and parallel region-based implementations. Experimental results from on aircraft scanner data set are presented, as is a discussioon of proposed improvements to the segmentation algorithm.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
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  • 76
    Publikationsdatum: 2011-08-18
    Beschreibung: The scientific instruments comprising the OSTA-1 package flown on the second Shuttle mission (November 12-14, 1981) are listed, and the Shuttle Imaging Radar (SIR-A) experiments are examined in detail: SIR-A operated for 8 h and obtained images covering more than 10 million sq km at 40-m resolution. The images were recorded on photographic film and processed in holographic form at JPL, and data for Southern Europe and parts of Africa were distributed to French scientists by the Groupement pour le Developpement de la Teledetection Aerospatiale. The main areas of research were environmental studies and geology, and the SIR-A images were used in combination with aerial photography, thematic maps, and Landsat images. The technical specifications of the SIR-B radar planned for STS-17 in 1984 are compared with those of SIR-A and Seasat SAR in tables.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: Societe Francaise de Photogrammetrie et de Teledetection, Bulletin (ISSN 0244-6014); 91, 1; 5-9
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  • 77
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    Publikationsdatum: 2011-08-18
    Beschreibung: A solution is presented for the backscatter (monostatic) radar cross section of dielectric disks of arbitrary shape, thickness, and dielectric constant. The result is obtained by employing a Kirchhoff-type approximation to obtain the fields inside the disk. The internal fields induce polarization and conduction currents from which the scattered fields and the radar cross section can be computed. The solution for the radar cross section obtained in this manner will be shown to agree with known results in the special cases of normal incidence, thin disks, and perfect conductivity. It will also be shown that the solution can be written as a product of the reflection coefficient of an identically oriented slab times the physical optics solution for the backscatter cross section of a perfectly conducting disk of the same shape. This result follows directly from the Kirchhoff-type approximation without additional assumptions.
    Schlagwort(e): COMMUNICATIONS AND RADAR
    Materialart: IEEE Transactions on Antennas and Propagation (ISSN 0018-926X); AP-32; 6-12
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  • 78
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    Publikationsdatum: 2011-08-18
    Beschreibung: The use of remote sensing in resource exploration is reviewed, with emphasis placed on new developments in high spectral resolution remote-sensing techniques for mineralogic and vegetation mapping. Topics discussed include aerial photography and satellite remote sensing, concepts and principles of spectral data collection, spectral properties of rocks and minerals, spectral properties of vegetation, and botanical aspects of geochemical stress. The discussion also covers applications of Landsat multispectral scanner data to lithologic and geobotanic studies and the future development of data acquisition and data interpretation techniques.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: Economic Geology and Society of Economic Geologists, Bulletin (ISSN 0361-0128); 78; 573-590
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  • 79
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    Publikationsdatum: 2011-08-18
    Beschreibung: A conceptual design for a Land Mobile Satellite System (LMSS) for the 1990s is presented. LMSS involves small tranceivers accessing satellites directly, with ground reception through small car-top antennas. The satellite would have a large antenna and blanket coverage areas in the UHF. The call may originate from a home, be carried by wire to a gateway, transmitted to satellite on the S-band, converted to UHF on the satellite, and transmitted to the vehicle. The system design is constrained by the number of users in an area during the busiest hours, Shuttle storage, controllability factors, and the total area served. A 55-m antenna has been selected, with 87 spot beams and two 10 MHz UHF bands in the 806-890 MHz band. A 17 dB interbeam isolation level is required, implying that sufficient sub-bands can be generated to assure 8265 total channels. The mobile satellite (MSAT) would have an 83 m mast lower segment, a 34 m upper segment, and a second, 10 m antenna made of a deployable mesh. Various antenna function modes are considered.
    Schlagwort(e): COMMUNICATIONS AND RADAR
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  • 80
    Publikationsdatum: 2011-08-18
    Beschreibung: In this paper, results of a Monte Carlo simulation of the effect of noise on the relationship between the microwave emissivity of soil and its moisture content are presented. It is found that whenever the magnitude of the noise for the independent variable, in this case the soil moisture, is increased, both the slope of the regression and the correlation coefficient decrease. In particular, when the noise has magnitude equivalent to a coefficient of variation of 0.25, the slope and correlation coefficient are in good agreement with those obtained from the data of a 21-cm airborne microwave radiometer which was flown over a test site in hand county, South Dakota. The comparison was made using a linear relationship to determine the estimated emissivity from the ground measurements of soil moisture. The linear relationship was derived from a radiative transfer model calculation of the microwave emissivities using realistic soil-moisture profiles. The effect of surface roughness was included in the relationship, and the variability of the surface roughness was also simulated by a Monte Carlo technique.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: IEEE Transactions on Geoscience and Remote Sensing (ISSN 0196-2892); GE-21; 473-479
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  • 81
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    Publikationsdatum: 2011-08-18
    Beschreibung: The error probability performance of differential detection of narrow-band FM is determined and compared with the analogous results for limiter-discriminator detection of the same modulation. It is shown that over a large class of benign and hostile environments, e.g., Gaussian IF filter, AWGN, partial-band noise jamming, the differential detector offers no theoretical performance advantage over the limiter-discriminator receiver with integrate-and-dump postdetection filtering.
    Schlagwort(e): COMMUNICATIONS AND RADAR
    Materialart: IEEE Transactions on Communications (ISSN 0090-6778); COM-31; 1227-123
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  • 82
    Publikationsdatum: 2011-08-18
    Beschreibung: Automated information extraction procedures for analysis of multitemporal Landsat data in non-U.S. crop inventory and monitoring are reviewed. Experiments to develop and evaluate crop area estimation technologies for spring small grains, summer crops, corn, and soybeans are discussed. Previously announced in STAR as N82-32793
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
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  • 83
    Publikationsdatum: 2011-08-18
    Beschreibung: Agriculture, which occupies a vital position in the economy of the State of California, depends crucially on the available water. The California Department of Water Resources (DWR) is, therefore, greatly concerned with the total water requirements for agricultural applications. In view of the limitations of an area-limited, single-date survey system, the DWR has been cooperating with NASA and the University of California in a study of the applicability of Landsat imagery and digital data as an aid in making decisions concerning the management of water resources. Attention is given to a statewide inventory of irrigated land, computer-assisted estimation and mapping of irrigated land, and a crop type analysis using Landsat digital data.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
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  • 84
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    Publikationsdatum: 2011-08-18
    Beschreibung: The development of a preprocessing unit for Landsat Thematic Mapper (TM) data for the Earth Observations Data Laboratory at Johnson Space Center is reported. The background of the project is sketched, including the greatly increased data-handling requirements compared to MSS, the influence of the JPL VICAR system on the system design, and the completeness of the GSFC SCROUNGE (LASLIB) TM data tapes. The design approach and realization are discussed, and the performance and transportability of the preprocessor programs (totaling about 2000 lines of source code in FORTRAN and IBM Assembly languages) are indicated. The system is able to read the TM image tapes, extract areas of interest to particular studies, and register the extracted imagery to suitable references. Ancillary programs include image enhancement, rotation, filtering and pixel-size modification.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
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  • 85
    Publikationsdatum: 2011-08-18
    Beschreibung: Features of the NASA Regional Application Program for providing state and local land management agencies an opportunity to assess the usefulness of emerging remote sensing technology are described. The Program guidelines necessitated configuring software for local facilities, assuring that the aggncy involved furnished manpower, and applying the technology to local needs. The study focused on the southwestern U.S., particularly for purposes of water management, federal/state ownership/policy, energy development, environmental impact issues, timber and range inventory, fire control, and urban expansion. Demonstration projects were conducted in various topics, according to the state surveyed, with the success of the projects determined by the willingness of the agencies to continue with the technology, which happened in several cases.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
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  • 86
    Publikationsdatum: 2011-08-18
    Beschreibung: The technique outlined in this paper is intended to eliminate the problems of cochannel interference and uniform geographic distribution of user channels which arise in conventional designs for a multiple spot beam communication satellite to serve mobile telephony users across the CONUS. By time multiplexing FM/FDMA signal ensembles so that only those beams operating on distinct frequency subbands are allowed to transmit concurrently, cochannel interference arising from simultaneous frequency subband reuse is precluded. Thus, time disjoint frequency reuse is accomplished over a repetitive sequence of fixed time slots. By assigning different size subbands to each time slot, a market of nonuniform users can be accommodated. The technique results in a greatly simplified antenna feed system design for the satellite, at a cost of imposing the need for time slot synchronization on the mobile FM receivers whose ability for rejecting adjacent channel interference is somewhat diminished.
    Schlagwort(e): COMMUNICATIONS AND RADAR
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  • 87
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    Publikationsdatum: 2011-08-18
    Beschreibung: A statistical correlation technique is applied to the retrieval of vertical moisture profiles from downlooking radiometric measurements of atmospheric radiation at microwave wavelengths. Only an optimum subset of available radiometer channels is selected for estimating water vapor at specific pressure levels. To test its validity the algorithm was applied, in a numerical experiment, to 50 independent tropical radiosondes over a sea surface. It was also used to retrieve continuous sequences of atmospheric moisture profiles from a set of data obtained with a 4-channel microwave radiometer carried aboard an aircraft over a land surface.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: ESA IGARSS 84. Remote Sensing: From Res. towards Operational Use, Vol. 1; p 449-451
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  • 88
    Publikationsdatum: 2011-08-18
    Beschreibung: The SEASAT altimeter (ALT), scatterometer (SASS), and scanning microwave multichannel radiometer (SMMR) measured sea surface wind speed. During the satellite lifetime from June to October 1978, the Austral winter, the highest wind speeds were recorded in the Southern Ocean. Three-month, monthly, and three-day surface wind speed fields deduced from the three Seasat wind speed sensors are compared. The monthly and three-day fields show a pronounced mesoscale (1000 km) variability in wind speed. At all space and time scales analyzed, differences of 40% are found in the magnitude of the wind speed features, with the ALT consistently yielding the lowest wind speed and the SMMR the highest.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: ESA IGARSS 84. Remote Sensing: From Res. towards Operational Use, Vol. 1; p 403-409
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  • 89
    Publikationsdatum: 2011-08-18
    Beschreibung: Passive microwave measurements of the Bering Sea were made with the NASA CV-990 airborne laboratory during February. Microwave data were obtained with imaging and dual-polarized, fixed-beam radiometers in a range of frequencies from 10 to 183 GHz. The high resolution imagery at 92 GHz provides a particularly good description of the marginal ice zone delineating regions of open water, ice compactness, and ice-edge structure. Analysis of the fixed-beam data shows that spectral differences increase with a decrease in ice thickness. Polarization at 18 and 37 GHz distinguishes among new, young, and first-year sea ice types.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: ESA IGARSS 84. Remote Sensing: From Res. towards Operational Use, Vol. 1; p 379-384
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  • 90
    Publikationsdatum: 2011-08-18
    Beschreibung: Data acquired with the Scanning Multichannel Microwave Radiometer (SMMR) on board the Nimbus-7 Satellite for a six-week period in Fram Strait were analyzed with a procedure for calculating sea ice concentration, multiyear fraction, and ice temperature. Calculations were compared with independent observations made on the surface and from aircraft to check the validity of the calculations based on SMMR data. The calculation of multiyear fraction, which was known to be invalid near the melting point of sea ice, is discussed. The indication of multiyear ice is found to disappear a number of times, presumably corresponding to freeze/thaw cycles which occurred in this time period.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: ESA IGARSS 84. Remote Sensing: From Res. towards Operational Use, Vol. 1; p 373-378
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  • 91
    Publikationsdatum: 2011-08-18
    Beschreibung: The California Integrated Remote Sensing System's San Bernardino County Project was devised to study the utilization of a data base at a number of jurisdictional levels. The present paper discusses the implementation of change-detection and masking techniques in the updating of Landsat-derived land-cover maps. A baseline landcover classification was first created from a 1976 image, then the adjusted 1976 image was compared with a 1979 scene by the techniques of (1) multidate image classification, (2) difference image-distribution tails thresholding, (3) difference image classification, and (4) multi-dimensional chi-square analysis of a difference image. The union of the results of methods 1, 3 and 4 was used to create a mask of possible change areas between 1976 and 1979, which served to limit analysis of the update image and reduce comparison errors in unchanged areas. The techniques of spatial smoothing of change-detection products, and of combining results of difference change-detection algorithms are also shown to improve Landsat change-detection accuracies.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
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  • 92
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    Publikationsdatum: 2011-08-18
    Beschreibung: A technique is examined for improving the comparability of Landsat multisppectral scanner (MSS) data acquired on different dates. The technique involves conversion of digital brightness counts to relative radiance values measured in energy units (milliwatts per square centimeter-steradian). The statistical data of signature from 23 land cover (or biomass) classifications derived from all three Landsats were compared before and after the radiance normalization. Significant convergence occurred among the data sets for mean spectral values and the variances associated with each of seven major land cover types for MSS bands 4, 5, and 7. Overall, the variance attributed to the sensor component was reduced from 5.39 to 2.69 percent, with the largest decrease occurring in band 4 (14.4 percent to 3.7 percent).
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
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  • 93
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    In:  Other Sources
    Publikationsdatum: 2011-08-18
    Beschreibung: Soil moisture budgets at the Earth's surface were investigated based on soil and atmospheric temperature variations. A number of data sets were plotted and statistically analyzed in order to accentuate the existence and the characteristics of mesoscale soil temperature extrema variations and their relations to other parameters. The correlations between diurnal temperature extrema for air and soil in drought and non-drought periods appear to follow different characteristic patterns, allowing an inference of soil moisture content from temperature data. The recovery of temperature extrema after a precipitation event also follows a characteristic power curve rise between two limiting values which is an indicator of evaporation rates. If these indicators are applied universally to regional temperature data, soil moisture content or drought conditions can be inferred directly from temperature measurements.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: Res. Activities of the Geodyn. Branch; 6 p
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
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  • 94
    Publikationsdatum: 2011-08-18
    Beschreibung: The spaceborne gravity gradiometer is a potential sensor for mapping the fine structure of the Earth's gravity field. Error analyses were performed to investigate the accuracy of the determination of the Earth's gravity field from a gravity field satellite mission. The orbital height of the spacecraft is the dominating parameter as far as gravity field resolution and accuracies are concerned.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: Res. Activities of the Geodyn. Branch; 6 p
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
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  • 95
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    In:  Other Sources
    Publikationsdatum: 2011-08-18
    Beschreibung: The capability of spaceborne altimetry to record the level, or monitor changes in the level, of inland seas was assessed. SEASAT altimetry data from Lake Baikal in Siberia; the Caspian, Black, and Aral Seas in the southern Soviet Union; the Great Salt Lake in the United States; lakes and reservoirs in northwestern and central China; and snow cover in northwestern India and on the Tibetan Plateau were examined.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: Res. Activities of the Geodyn. Branch; 6 p
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
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  • 96
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    In:  Other Sources
    Publikationsdatum: 2011-08-18
    Beschreibung: A simple interactive biosphere is presented based on an electrical analog of turbulent transport processes that produce heat and moisture fluxes between land and the atmosphere. A network of resistances that effect temperature or vapor pressure fluxes are identified and entered into the quasi steady state equations. A set of solutions that depict a realistic diurnal cycle is included.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: Res. Rev., 1983; p 285-291
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
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  • 97
    Publikationsdatum: 2011-08-19
    Beschreibung: Changes in leaf spectra caused by mineralization under different conditions of preservation are measured using a three-band portable radiometer which simulates three Thematic Mapper bands 3, 4, and 5. Daily spectral measurements of white oak (Quercus alba) leaves did not distinguish among the fresh, bottled, and bagged vegetation in the spectral bands 3 and 5 for up to four days after collection. The reflected energy of the preserved vegetation increased thereafter, reportedly due to the loss of chlorophyll and dehydration. It is concluded that the measurement procedure is sufficiently sensitive as to discern documented patterns of variation in reflectance measurements.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: Photogrammetric Engineering and Remote Sensing (ISSN 0099-1112); 50; 1737-174
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
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  • 98
    Publikationsdatum: 2011-08-19
    Beschreibung: An airborne multispectral scanner, operating in the same spectral channels as the Landsat Thematic Mapper (TM), was used in a region east of Denver, CO, for a simulation test performed in the framework of using TM to discriminate the level I and level II classes. It is noted that at the 30-m spatial resolution of the Thematic Mapper Simulator (TMS) the overall discrimination for such classes as commercial/industrial land, rangeland, irrigated sod, irrigated alfalfa, and irrigated pasture was superior to that of the Landsat Multispectral Scanner, primarily due to four added spectral bands. For residential and other spectrally heterogeneous classes, however, the higher resolution of TMS resulted in increased variability within the class and a larger spectral overlap.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: Photogrammetric Engineering and Remote Sensing (ISSN 0099-1112); 50; 1713-172
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
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  • 99
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    In:  Other Sources
    Publikationsdatum: 2011-08-19
    Beschreibung: Binary cyclic redundancy codes for feedback communication over noisy digital links are considered. The standard 16 bit American Data and Computer Communication Protocol (ADCCP) polynomial is designed for digital links which already have a low input bit error probability. For file transfer between personal computers over telephone circuits, the quality of resulting digital circuit may be much lower. The 3 byte (24 bit) and 4 byte (32 bit) polynomials are considered. Generator polynomials of a certain class have minimum weight and yet achieve the bound on minimum distance for arbitrary codes. Particular choices for 24 bit and 32 bit redundancies are exhibited: of weight and distance 6 in the 24-bit case; and weight 10 and distance 8 in the 32-bit case.
    Schlagwort(e): COMMUNICATIONS AND RADAR
    Materialart: IEEE Transactions on Information Theory (ISSN 0018-9448); IT-30; 865-867
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
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  • 100
    Publikationsdatum: 2011-08-19
    Beschreibung: The Earth Resources Observation System (EROS) Program was established by the U.S. Department of the Interior in 1966 under the administration of the Geological Survey. It is primarily concerned with the application of remote sensing techniques for the management of natural resources. The retrieval system employed to search the EROS database is called INORAC (Inquiry, Ordering, and Accounting). A description is given of the types of images identified in EROS, taking into account Landsat imagery, Skylab images, Gemini/Apollo photography, and NASA aerial photography. Attention is given to retrieval commands, geographic coordinate searching, refinement techniques, various online functions, and questions regarding the access to the EROS Main Image File.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: Database (ISSN 0162-4105); 7; 35-52
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
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