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  • Other Sources  (1,875)
  • AIRCRAFT  (1,345)
  • Cell & Developmental Biology
  • Deutschland
  • EARTH RESOURCES AND REMOTE SENSING
  • Life Sciences (General)
  • 1970-1974  (1,875)
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Source
Keywords
Years
Year
  • 1
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    Phänologie und Reife des Körnermaises in der Bundesrepublik Deutschland in Abhängigkeit von Witterung und Klima (1974)
    In:  Diss. Weihenstephan.
    Details
    Publication Date: 1974
    Description: Analyse des Klimas und der Witterung in Bezug zu den Maiserträgen des Versuchsfeldes KATASTER-BESCHREIBUNG: KATASTER-DETAIL:
    Keywords: Deutschland ; 1956-74 ; Ertrag ; Klima ; Korrelationsmethode ; Mais ; Niederschlag ; Temperatur
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    BIBLIOGRAPHY INKA BB
  • 2
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    Image data processing of earth resources management (1974)
    In:  CASI
    Details
    Publication Date: 2006-05-07
    Description: Various image processing and information extraction systems are described along with the design and operation of an interactive multispectral information system, IMAGE 100. Analyses of ERTS data, using IMAGE 100, over a number of U.S. sites are presented. The following analyses are included: investigations of crop inventory and management using remote sensing; and (2) land cover classification for environmental impact assessments. Results show that useful information is provided by IMAGE 100 analyses of ERTS data in digital form.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: Chamber of Commerce Proc. of the 1st 1974 Technol. Transfer Conf.; p 201-218
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    NASA TECHNICAL REPORTS
  • 3
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    Aircraft noise in the region of the Bucharest-Otopeni Airport (1974)
    In:  CASI
    Details
    Publication Date: 2006-01-11
    Description: Aircraft noise, especially in the region adjoining airports, constitutes a problem that will be aggravated in the near future because of increasing aircraft traffic and the appearance of new types of large tonnage aircraft with continuously increasing powers and speeds. Criteria for the evaluation of aircraft noise are reported and some results of studies carried out in the region of Bucharest-Otopeni Airport are detailed.
    Keywords: AIRCRAFT
    Type: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 233-237
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    NASA TECHNICAL REPORTS
  • 4
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    Application of advanced signal processing techniques to the rectification and registration of spaceborne imagery (1974)
    In:  CASI
    Details
    Publication Date: 2006-05-07
    Description: The development of an ERTS/MSS image processing system responsive to the needs of the user community is discussed. An overview of the TRW ERTS/MSS processor is presented, followed by a more detailed discussion of image processing functions satisfied by the system. The particular functions chosen for discussion are evolved from advanced signal processing techniques rooted in the areas of communication and control. These examples show how classical aerospace technology can be transferred to solve the more contemporary problems confronting the users of spaceborne imagery.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: Chamber of Commerce Proc. of the 1st 1974 Technol. Transfer Conf.; p 245-255
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  • 5
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    The application of natural science data to land management decision-making (1974)
    In:  CASI
    Details
    Publication Date: 2006-05-07
    Description: A natural environmental analysis process which allows the decision maker to know the probable consequences of a decision prior to the act is developed. Emphasis is placed on the fit between the natural environment and the social, economic, and functional attributes of man's communities and the transition from nature in its present state to various forms and intensities of development. Applications of the analysis are examined. It is concluded that the analysis is a workable system for land use management.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: Chamber of Commerce Proc. of the 1st 1974 Technol. Transfer Conf.; p 219-228
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    NASA TECHNICAL REPORTS
  • 6
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    Use of cross-correlation measurements to investigate noise generating regions of a real jet engine and a model jet (1974)
    In:  CASI
    Details
    Publication Date: 2011-10-14
    Description: Cross-correlations are reported of the jet static pressure fluctuations (as measured with a B and K microphone fitted with a nose cone), with the far-field radiated sound pressure. These measurements were made for various probe positions and a large number of far-field positions (at various angles). In addition, the tests were run for a number of different jet exit velocities. The measured, normalized cross-correlation functions vary between 0.004 and 0.155. These values depend upon the angular position of the far-field microphone, the jet exit Mach number, and the position of the probe. In addition, the cross-correlation technique was employed to study the symmetry of the far-field radiated sound about the jet axis. Third-octave analyses of both the probe signal and the far-field radiated sound were made. This is the first time correlation measurements have been made on a jet engine. In addition, a report is given on an extensive noise survey of a model jet. The correlations are related to sound source functions and jet source regions are discussed.
    Keywords: AIRCRAFT
    Type: AGARD Noise Mech.; 13 p
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  • 7
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    Comment on satellite altimeter data (1974)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: SKYLAB mission SEASAT-B altimeter observations in combination with surface gravity measurements provide useful data on the marine geoid and expected ocean perturbations from analyses of seamount structures.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA, Washington Seasat-A Sci. Contrib.; p 38
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  • 8
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    Baring high-albedo soils by overgrazing - A hypothesized desertification mechanism (1974)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: Observations are reported of high-albedo soils denuded by overgrazing which appear bright, in high contrast to regions covered by natural vegetation. Measurements and modeling show that the denuded surfaces are cooler, when compared under sunlit conditions. This observed 'thermal depression' effect should, on theoretical grounds, result in a decreased lifting of air necessary for cloud formation and precipitation, and thus lead to regional climatic desertification.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: Science; 186; Nov. 8
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  • 9
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    Performance of an inlet for an integrated scramjet concept (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: Review of the results of an experimental investigation of the performance of an inlet for an integrated scramjet engine concept at Mach 6. Following a description of the inlet design and test model, the Mach 6 experimental results obtained are presented in terms of integrated performance parameters.
    Keywords: AIRCRAFT
    Type: Journal of Aircraft; 11; Sept
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    NASA TECHNICAL REPORTS
  • 10
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    Effect of upper-surface blowing on static longitudinal stability of a swept wing (1974)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: A low-speed wind-tunnel investigation was conducted on a sharp-edged 75 deg delta wing, to determine the effect of upper-surface blowing on static longitudinal stability characteristics. The model incorporated nozzles, located at 0.50 mean aerodynamic chord length, supplied by compressed air to provide blowing on the upper surface. A full span trailing-edge flap was also tested as an additional high-lift device. The angle of attack was varied from 0 to 24 deg for a range of thrust coefficients from 0 to 0.45. The results of the static force tests showed that favorable increments in static longitudinal stability and lift were obtained using upper-surface blowing.
    Keywords: AIRCRAFT
    Type: Journal of Aircraft; 11; Sept
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  • 11
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    RPVs - Exploring civilian applications (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: Discussion of the civilian application possibilities for remotely piloted vehicle (RPV) systems. Following a listing of all possible desert, coastal, forest, agricultural, and urban RPV missions, a thorough examination is presented of such possible RPV aircraft applications as those of forest-fire detection and mapping. Some of the major obstacles to such civilian missions are also reviewed.
    Keywords: AIRCRAFT
    Type: Astronautics and Aeronautics; 12; Sept
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  • 12
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    V/STOL flying qualities research using the X-22A (1974)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: The X-22A has four ducted propellers and four engines. The engines are connected to a common system of rotating shafts which distribute propulsive power to the four propellers. Changes in the direction of the thrust vector are accomplished by rotating the ducts, which are interconnected so that all rotate through the same angle. Thrust magnitude is determined by a collective pitch lever, very similar to a helicopter. There are four variable stability system (VSS) controllers: thrust, pitch, roll, and yaw, and three artificial feel servos for the evaluation pilot cockpit controls, each employing electrohydraulic servos. Longitudinal flying qualities for STOL landing approach, and lateral-directional flying qualities and control power requirements for STOL landing approach are discussed. Attention is given to the data acquisition and processing system.
    Keywords: AIRCRAFT
    Type: Society of Experimental Test Pilots; vol. 12
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  • 13
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    Suspension-line wave motion during the lines-first parachute unfurling process (1974)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: A new mathematical approach to modeling the lines-first parachute unfurling process is presented. The unfurling process is treated as two distinct phases: a suspension-line unfurling phase, during which a massless-spring model of the suspension-line elasticity may be employed; and a canopy unfurling phase, during which a formulation considering suspension-line wave mechanics is employed. Histories of unfurled length and tension at the vehicle obtained using the model are compared with flight test data, and generally good agreement is observed.
    Keywords: AIRCRAFT
    Type: AIAA Journal; 12; Jan. 197
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  • 14
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    Transonic transport wings - Oblique or swept (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: A comparative evaluation of fixed-geometry and variable-sweep wing designs, a fixed delta wing, and oblique wings with a single body or two bodies suggests that an oblique wing is preferable in a transonic transport aircraft in terms of gross weight, fuel consumption, and aircraft noise, and also shows an acceptable aeroelastic stability. Further studies are, however, needed to develop the full potential of the oblique-wing concept, including its economic implications.
    Keywords: AIRCRAFT
    Type: Astronautics and Aeronautics; 12; Jan. 197
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    NASA TECHNICAL REPORTS
  • 15
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    Navy participation in the development of airframe parameter identification techniques (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: The Navy is currently involved in the development of advanced parameter identification techniques for use in aircraft flight testing and refinement of aircraft dynamic systems modeling. An overview is presented of the Navy's research programs, capabilities, and facilities. The use of parameter identification techniques are related to the flight testing, development, and simulation of aircraft and aircraft systems in the areas of flying qualities, automatic flight controls, flight dynamics, and advanced landing systems. Preliminary analytical and flight test results are presented. The impact that new parameter identification technology has on Navy flight test philosophy is discussed. Future plans are outlined.
    Keywords: AIRCRAFT
    Type: NASA. Flight Res. Center Parameter Estimation Tech. and Appl. in Aircraft Flight Testing; p 39-42
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  • 16
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    Remote sensing and snowpack management (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: The present work describes the use of an airborne electromagnetic sensing system for measuring snowpack depth, density, and water content. A transmitter sends a sequence of pulses of stepped frequencies, and the reflections are measured by a sensitive receiver. The combination of the snowpack and the earth interacts with the electromagnetic wave so as to modify the characteristics of the reflected signals. The variation of the reflected intensity with frequency provides the desired data. A theoretical analysis of return signal and snowpack parameter relationships is given, and the results of experimental verification of the theory are discussed.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: American Water Works Association; vol. 66
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    NASA TECHNICAL REPORTS
  • 17
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    Wheat - Its growth and disease severity as deduced from ERTS-1 (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: The spectral reflectance of a cropped surface changes as the plant develops. An indicator of crop growth is leaf area index (ratio of green leaf area to soil area). The leaf area index, disease severity, and yield were determined for several winter wheat fields in Kansas during the 1973 growing season. Multispectral scanner (MSS) data from Earth Resources Technology Satellite-1 (ERTS-1) showed a high correlation (r greater than or equal to 0.90) between crop growth and MSS4/MSS5, and crop growth and MSS5/MSS6. Wheat disease severity and yields were significantly correlated at the 5% level with MSS4/MSS6 and with MSS4/MSS7. Further investigation is required before ERTS imagery can be routinely used detecting and estimating disease severity and yield reduction.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: Remote Sensing of Environment; 3; 4, 19; 1974
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    NASA TECHNICAL REPORTS
  • 18
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    Microwave maps of the polar ice of the earth (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: Synoptic views of the entire polar regions of earth have been obtained free of the usual persistent cloud cover using a scanning microwave radiometer operating at a wavelength of 1.55 cm on board the Nimbus-5 satellite. Three different views at each pole are presented utilizing data obtained at approximately one-month intervals from December 1972 to February 1973. Large discrepancies exist between the long-term ice cover depicted in various atlases and the actual extent of the canopies. The distribution of multiyear ice in the north polar region is markedly different from that predicted by existing ice dynamics models. Irregularities in the edge of the Antarctic sea ice pack occur that have neither been observed previously nor anticipated. The brightness temperatures of the Greenland and Antarctic glaciers show interesting contours probably related to the ice and snow morphologic structure.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: American Meteorological Society; vol. 55
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    NASA TECHNICAL REPORTS
  • 19
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    Contribution of space platforms to a ground and airborne remote-sensing programme over active Italian volcanoes (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: ERTS-1 imagery of the volcanic areas of southern Italy was used primarily for the evaluation of space platform capabilties in the domains of regional geology, soil and rock-type classification and, more generally, to study the environment of active volcanoes. The test sites were selected and equipped primarily to monitor thermal emission, but ground truth data was also collected in other domains (reflectance of rocks, soils and vegetation). The test areas were overflown with a two channel thermal scanner, while a thermo camera was used on the ground to monitor the hot spots. The primary goal of this survey was to plot the changes in thermal emission with time in the framework of a research program for the surveillance of active volcanoes. However, another task was an evaluation of emissivity changes by comparing the outputs of the two thermal channels. These results were compared with the reflectance changes observed on multispectral ERTS-1 imagery.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: ESRO European Earth-Resources Satellite Expts.; p 185-197
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    NASA TECHNICAL REPORTS
  • 20
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    Infrared remote sounding (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: Atmospheric radiation was measured as a function of wavelength, position, angle, and time. Radiation was determined by temperature, cloud (aerosol), composition, and surface emissivity measurements. The theory of radiative transfer is reviewed, along with retrieval methods. Instruments onboard space probes for infrared remote sounding of planetary atmospheres are also described.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: Calif. Univ. Proc. of the UCLA Intern. Conf. on Radiation and Remote Probing of the Atmosphere; p 471-506
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    NASA TECHNICAL REPORTS
  • 21
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    Refinement of the Goloseyev catalog point coordinates in the limb zone and determination of point coordinates on the back side of the moon (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: Lunar photography from Zond 6 showed half the side of the moon which is not visible from the earth, and this made it possible to construct a photogrammetric grid encompassing the entire Western Hemisphere and referenced to points of the visible side, whose coordinates were taken from the Goloseyev catalog. The problem was solved using two pictures taken from approximately 9000 km above the lunar surface. The photogrammetric grid was constructed by joint statistical analysis of the measurements of both pictures and the selenographic coordinates of the catalog points. A special algorithm was developed and a program compiled realizing the maximum likelihood method which permitted working with up to 120 catalog points simultaneously.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: Space Iconics (NASA-TT-F-798); p 257-272
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  • 22
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    Determination of selenographic coordinates of lunar surface points from single pictures obtained from Zond 6 (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: Pictures of the lunar surface with an image of practically the entire lunar limb were obtained from the Zond 6 spacecraft. During the time of exposure, the entire lunar surface covered by these photographs was illuminated by the sun. Such single pictures were used to find the external orientation elements and selenographic coordinates of the photographed lunar surface points. The selenographic coordinate system was specified by the Goloseyev catalog and was realized by points of this catalog identified on the pictures and termed reference points. Craters located on the invisible side of the moon and also other points of the Goloseyev catalog, which could be used as control points, were taken as the points being determined. The technique used to compute the selenographic coordinates of the points is outlined.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: Space Iconics (NASA-TT-F-798); p 272-282
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  • 23
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    Determination of dynamic corrections to point coordinates of photographs obtained by the Zond 6 and Zond 8 spacecraft (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: The linear and angular motions of the Zond 6 and Zond 8 spacecraft imaging camera during the exposure cause displacements of the optical image points. In the case of instantaneous exposure of each individual point and the nonsimultaneous exposure of the complete frame, this leads to finite geometric shifts of the points without causing blurring of the photographic image. Therefore, when measuring the resulting photographic pictures, the problem arises of reducing the picture point positions to a common instant of time. This reduction is performed by means of dynamic corrections to the measured picture point coordinates. These corrections are found by using formulas of dynamic photogrammetry. Their use with the Zond space probe photographs is described.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: Space Iconics (NASA-TT-F-798); p 245-257
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  • 24
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    Evaluating the accuracy of selenodesic reference grids (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: Estimates were made of the accuracy of reference point grids using the technique of calculating the errors from theoretical analysis. Factors taken into consideration were: telescope accuracy, number of photographs, and libration amplitude. To solve the problem, formulas were used for the relationship between the coordinates of lunar surface points and their images on the photograph.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: Space Iconics (NASA-TT-F-798); p 231-245
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  • 25
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    Identification characteristics of certain lunar relief forms on pictures obtained from spacecraft (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: This investigation was restricted to the determination of recognitional characteristics of a single type of relief form, dimple craters on the surface of maria. These craters were arbitrarily considered as closed, negative relief forms, circular in plan-view, and symmetric relative to the center. Two techniques were used to determine the shadow configuration in the craters: (1) experimental determination of the shadow edge by illuminating the models of different profile shapes with a parallel light beam; and (2) geometric construction of the shadow edge using a vertical section of the formation in the direction of the solar rays. A morphological map of the surface which includes the following factors can be compiled using the proposed identification technique: crater profile nature, crater diameter, ratio of diameter and depth, sharpness of the lip, and distribution density of the forms.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: Space Iconics (NASA-TT-F-798); p 205-215
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  • 26
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    Use of TV pictures obtained from weather satellites to study the geological structure of the earth (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: Results are presented of Soviet investigations into the use of television imagery obtained from meteorological satellites for the interpretation of tectonics, lithology, and structural properties of the earth. The area investigated encompassed the eastern part of Iran, and the western regions of Afghanistan and Pakistan. Interpretation of the features identified during the analysis was accomplished by comparing these features with physical, geographic, geological, and tectonic maps. It was concluded that television pictures of the earth from space can be used for geological and structural analysis.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: Space Iconics (NASA-TT-F-798); p 190-194
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  • 27
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    On the determination of certain astronomical, selenodesic, and gravitational parameters of the moon (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: A method was examined for joint construction of a selenocentric fundamental system which can be realized by a coordinate catalog of reference contour points uniformly positioned over the entire lunar surface, and determination of the parameters characterizing the gravitational field, rotation, and orbital motion of the moon. Characteristic of the problem formulation is the introduction of a new complex of inconometric measurements which can be made using pictures obtained from an artificial lunar satellite. The proposed method can be used to solve similar problems on any other planet for which surface images can be obtained from a spacecraft. Characteristic of the proposed technique for solving the problem is the joint statistical analysis of all forms of measurements: orbital iconometric, earth-based trajectory, and also a priori information on the parameters in question which is known from earth-based astronomical studies.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: Space Iconics (NASA-TT-F-798); p 215-231
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  • 28
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    Experience in integrated geological and geographical interpretation of space photographs obtained in the USSR (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: Two examples of regional interpretation of imagery acquired from satellite photographic and television systems are discussed. The imagery was taken aboard the Zond 7 and Kosmos satellites, and depicted; (1) sand and dust storm activity in the eastern Mediterranean Sea area; and (2) landscape and structural properties of territory of southwestern United States and northwestern Mexico.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: Space Iconics (NASA-TT-F-798); p 182-189
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  • 29
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    Geological and geophysical studies from space and prospects for their development (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: The possibilities of using images obtained by devices which detect the reflected and self-radiation of the the earth's surface and atmosphere in other parts of the spectrum, other than visible, were analyzed. Considered were: (1) infrared; (2) radiothermal; and (3) magnetic field.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: Space Iconics (NASA-TT-F-798); p 174-181
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  • 30
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    System for electronic transformation and geographic correlation of satellite television information (1974)
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    Publication Date: 2011-08-16
    Description: An electronic transformation and correlation system has been developed for the Meteor space weather system which provides transformation and scaling of the original picture, accounts for satellite flight altitude and inclinations of the optical axes of the transmitting devices, and simultaneously superposes the geographical coordinate grid on the transformed picture.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: Space Iconics (NASA-TT-F-798); p 155-164
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  • 31
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    Geographical correlation of TV and IR images obtained from weather satellites (1974)
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    Publication Date: 2011-08-16
    Description: The requirements on the accuracy of geographical correlation of TV and IR cloud cover images are determined by the objective of the analysis of the weather information contained in these images. In the operational analysis case, the correlation accuracy need not be high. Errors of several tens of kilometers in determining the location of the cloud formation contours are considered acceptable in this case. Such correlation must be provided in real image reception time. Scientific studies require accurate correlation of the cloud formation contours. The errors in determining their position should be commensurate with the imaging system resolution. The geometric aspects of developing methods and equipment for geographical correlation of television and infrared images of cloud cover taken from Meteor satellites are discussed.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: Space Iconics (NASA-TT-F-798); p 146-155
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  • 32
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    Geographic correlation of television pictures obtained from weather satellites (1974)
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    Publication Date: 2011-08-16
    Description: The geographical control of satellite pictures, using the terminology of aerial photography, can be treated as the problem of analysis of a single picture with the objective of obtaining a ground contour map. Studies have shown the possibility and capability of the method of composing photographic maps from transformed television pictures. Optico-mechanical transformation solves the problem of geographical correlation for operational purposes. However, this technique does not compensate for electronic distortion, and accounts for earth sphericity only approximately. However, for certain purposes (studying ice drift), the maximum possible accuracy is required. Analytic geographical correlation methods using digital computers should be considered promising.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: Space Iconics (NASA-TT-F-798); p 143-145
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    Geometric distortions of autocollimation type scanners (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: One criterion of image quality is its geometric similarity to the control test. The ability of television, phototelevision, phototelegraphic, and other systems to transmit geometrically similar images is characterized by the geometric distortion coefficient. Linear distortions result from the inaccuracy of scanning mechanism element assembly, and distortions can be minimized during adjustment operations or may be easily compensated during image reception. Brief descriptions are given of the possible sources of nonlinear distortions which arise in these devices due to the scanning mechanism, objective distortion, or the nodding mirror.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: Space Iconics (NASA-TT-F-798); p 48-51
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    Geometric distortions of opticommercial panoramic television systems (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: One of the problems solvable by the spaceborne television system, topographical surveying, makes high demands on image quality, particularly on the geometric distortions introduced by the television camera. It is the geometric distortions which determine measurement accuracy and, consequently, the possibility of creating reliable planetary surface maps. Comparative analysis of the different television systems capable of solving the problem showed that the requirements on quality of the transmitted images are best satisfied by television cameras with opticomechanical scanning. The design of panoramic television systems and the process of image construction by the opticomechanical camera are discussed. Results indicate that panoramic television cameras have the necessary instrumental accuracy and permit determination of the direction to objects with an error practically equal to the resolution.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: Space Iconics (NASA-TT-F-798); p 51-59
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    Determining iconometric parameters of imaging devices using a wide-angle collimator (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: The problem of determining the iconometric parameters of the imaging device can be solved if the camera being calibrated is used to obtain the image of a group of reference points, the directions to which are known. In order to specify the imaging device coordinate system, it is sufficient in principle to obtain on the picture the images of three reference points which do not lie on a single straight line. Many more such points are required in order to determine the distortion corrections, and they must be distributed uniformly over the entire field of view of the camera being calibrated. Experimental studies were made using this technique to calibrate photographic and phototelevision systems. Evaluation of the results of these experiments permits recommending collimators for calibrating television and phototelevision imaging systems, and also short-focus small-format photographic cameras.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: Space Iconics (NASA-TT-F-798); p 41-47
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    Future development of IR thermovision weather satellite equipment (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: The self radiation of the surface being viewed is used for image synthesis in IR thermovision equipment. The installation of such equipment aboard weather satellites makes it possible to obtain cloud cover pictures of the earth's surface in a complete orbit, regardless of the illumination conditions, and also provides quantitative information on the underlying surface temperature and cloud top height. Such equipment is used successfully aboard the Soviet satellites of the Meteor system, and experimentally on the American satellites of the Nimbus series. With regard to surface resolution, the present-day IR weather satellite equipment is inferior to the television equipment. This is due primarily to the comparatively low detectivity of the IR detectors used. While IR equipment has several fundamental advantages in comparison with the conventional television equipment, the problem arises of determining the possibility for future development of weather satellite IR thermovision equipment. Criteria are examined for evaluating the quality of IR.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: Space Iconics (NASA-TT-F-798); p 29-41
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    Iconics and iconology (1974)
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    Publication Date: 2011-08-16
    Description: The term iconics covers the complex of methods and equipment for obtaining images, integrated on a common methodological basis. The concept combines such methods and equipment for obtaining images as photography, television, phototelevision, thermovision, and radar. The term iconics has been used previously, but in a narrower sense, as the name for the theory of image reproduction systems, primarily in the sense of their optimization. Iconics must include two branches; theoretical and practical. The system optimization problem then takes its place in theoretical iconics along with other problems. The term iconology has been proposed to cover the complex of image interpretation methods and equipment.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: Space Iconics (NASA-TT-F-798); p 1-20
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    Prospects for the development of phototelevision methods in space studies (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: In-space imaging of the surface of celestial bodies can be carried out by both television and photographic equipment. Television equipment of various types has the important property of being capable of transmitting imagery in real time. Frequently this is not possible because of the nature of information transmission over the spacecraft-ground communication line. The inadequate energy handling capacity of the communication lines usually requires storage of the video information aboard the spacecraft for subsequent transmission at a definite time and rate. For this purpose, the television camera can be connected with a magnetic memory, or the television imagery may be stored on photographic film. The television/photographic film system has been termed phototelevision. The choice of a system of one type or the other is dictated by several considerations, the most important of which are the size and weight characteristics, other conditions being the same (power consumption, reliability, etc.). The advantages and disadvantages of the two systems are discussed and examples are given of types of satellites on which the two types have been employed.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: Space Iconics (NASA-TT-F-798); p 21-28
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    Mineral resources, geological structures, and landform surveys (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: Since March 1973 there has been a shift in ERTS results in geology from the initial show-and-tell stage to a period in which scientific studies predominated, and now to an emphasis on effective applications having economic benefits and clearcut relevance to national needs. Many years will be spent on geological tasks resulting from ERTS alone; reconnaissance mapping in inaccessible regions, map revisions, regional or synoptic analysis of crustal fractures, assessment of dynamic surficial processes, systematic search for mineral wealth, use of sophisticated enhancement techniques, recognition of potential geologic hazards, and many more applications that still need to be defined.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: Third ERTS Symp., Vol. 2; p 147-167
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    Land use and mapping (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: The ERTS program provides data that can be used to derive information relative to the actual use of the land resource, in a practical and timely manner. ERTS data provide coverage of total land areas, and its repetitive nature enables the detection and monitoring of changes taking place in land use. Generally, the techniques and the procedures used to extract information from ERTS data may be categorized as pertaining to either the interpretations of ERTS imagery or to the use of digital data and computer techniques. Examples are given of the use of ERTS-1 data for land use classification in: (1) New England areas; (2) Chesapeake Bay and Washington, D.C.; (3) Mississippi Gulf Coast; (4) Los Angeles, California; (5) Houston, Texas; and (6) Phoenix, Arizona.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: Third ERTS Symp., Vol. 2; p 138-146
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    Water resources (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: ERTS-1 applications in snow and ice monitoring, surface water monitoring, including monitoring of wetland areas and flood inundated area mapping, and also watershed monitoring for runoff prediction are discussed. Results also indicate that geological features can be noted which relate to ground water. ERTS-1 data can be used successfully in operational situations by water resources management agencies.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: Third ERTS Symp., Vol. 2; p 126-137
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    Agriculture, forestry, range resources (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: The necessary elements to perform global inventories of agriculture, forestry, and range resources are being brought together through the use of satellites, sensors, computers, mathematics, and phenomenology. Results of ERTS-1 applications in these areas, as well as soil mapping, are described.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: Third ERTS Symp., Vol. 2; p 116-125
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    Automated strip mine and reclamation mapping from ERTS (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: In response to the urgent need for a faster and more economical means of generating strip mine and reclamation maps, a study was conducted to evaluate the suitability of using ERTS computer compatible tape for automatic mapping. The procedure uses computer target spectral recognition techniques as a basis for classification. The area encompassed by this investigation includes five counties in eastern Ohio that comprise nearly 7,500 square kilometers (3,000 square miles). The counties have been disrupted by coal mining since the early 1800's, and strip mining has been practiced in all of them. The environmental effects of strip mining are also discussed.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Goddard Space Flight Center Third ERTS Symp., Vol. 2; p 87-101
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    A review of initial investigations to utilize ERTS-1 data in determining the availability and distribution of living marine resources (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: The National Marine Fisheries Service has been studying the application of aerospace remote sensing to fisheries management and utilization for many years. The 15-month ERTS study began in July 1972 to: (1) determine the reliability of satellite and high altitude sensors to provide oceanographic parameters in coastal waters; (2) demonstrate the use of remotely-sensed oceanographic information to predict the distribution and abundance of adult menhaden; and (3) demonstrate the potential use of satellites for acquiring information for improving the harvest and management of fisheries resources. The study focused on a coastal area in the north-central portion of the Gulf of Mexico, including parts of Alabama, Mississippi, and Louisiana. The test area used in the final analysis was the Mississippi Sound and the area outside the barrier islands to approximately the 18-meter (10-fathom) curve.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Goddard Space Flight Center Third ERTS Symp., Vol. 2; p 76-86
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  • 45
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    ERTS program of the US Army Corps of Engineers (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: The Army Corps of Engineers research and development efforts associated with the ERTS Program are confined to applications of investigation, design, construction, operation, and maintenance of water resource projects. Problems investigated covered: (1) resource inventory; (2) environmental impact; (3) pollution monitoring; (4) water circulation; (5) sediment transport; (6) data collection systems; (7) engineering; and (8) model verification. These problem areas were investigated in relation to bays, reservoirs, lakes, rivers, coasts, and regions. ERTS-1 imagery has been extremely valuable in developing techniques and is now being used in everyday applications.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Goddard Space Flight Center Third ERTS Symp., Vol. 2; p 62-75
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    An evaluation of the suitability of ERTS data for the purposes of petroleum exploration (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: This investigation was undertaken to determine the types and amounts of information valuable to petroleum exploration that are extractable from ERTS data and to determine the cost of obtaining the information from ERTS relative to costs using traditional or conventional means. In particular, it was desirable to evaluate this new petroleum exploration tool in a geologically well-known area in order to assess its potential usefulness in an unknown area. In light of the current energy situation, it is felt that such an evaluation is important in order to best utilize technical efforts with customary exploration tools, by rapidly focusing attention on the most promising areas in order to reduce the time required to go through the exploration cycle and to maximize cost savings. The Anadarko Basin lies in western Oklahoma and the panhandle of Texas (Figure 1). It was chosen as a test site because there is a great deal of published information available on the surface and subsurface geology of the area, there are many known structures that act as traps for hydrocarbons, and it is similar to several other large epicontinental sedimentary basins.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Goddard Space Flight Center Third ERTS Symp., Vol. 2; p 50-61
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    Geologic evaluation and applications of ERTS-1 imagery over Georgia (1974)
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    Publication Date: 2011-08-16
    Description: Satellite imagery and other remote sensing tools and techniques have provided a powerful tool to assist geologic research; significantly increased the mapping efficiency of field geologists; shown new lineaments associated with known shear and fault zones; delineated new structural features; provided a tool to reevaluate tectonic history; helped to locate potential ground-water sources and areas of aquifer recharge; defined areas of geologic hazards; shown areas of heavy siltation in major reservoirs; and, by close interval repetition, aided in monitoring surface mine reclamation activities and the environmental protection of the intricate marshland system. The Georgia Geological Survey has been engaged in regional mapping for the new state geologic map. ERTS-1 images enlarged to compatible mapping scales have increased field geologic mapping efficiency by at least 25%. There are a number of areas where data from ERTS-1 imagery has allowed a notably higher level of precision than has been available with any amount of field work on the ground.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Goddard Space Flight Center Third ERTS Symp., Vol. 2; p 41-49
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    Environmental surveys in Alaska based upon ERTS data (1974)
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    Publication Date: 2011-08-16
    Description: Alaskan applications of ERTS data are summarized. Areas discussed are: (1) land use; (2) archaeology; (3) vegetation mapping; (4) ice reporting and mapping; (5) permafrost; (6) mineral and oil exploration; (7) geological surveys; (8) seismology; (9) geological faults and structures; (10) hydrology and water resources; (11) glaciology; (12) water circulation in Cook Inlet; and (13) fish and mammal populations.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Goddard Space Flight Center Third ERTS Symp., Vol. 2; p 12-40
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    The Canadian ERTS program (1974)
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    Publication Date: 2011-08-16
    Description: Under a four-year collaborative agreement between the United States and Canada, the Canada Centre for Remote Sensing (CCRS) reads out and distributes the ERTS data of Canada. The Canadian receiving station is at Prince Albert, Saskatchewan, and covers most of Canada except for the East Coast. Production statistics on Canadian ERTS imagery, a summary of several cost benefit case histories, and recommendations for the future of the international aspects of ERTS are discussed and evaluated.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Goddard Space Flight Center Third ERTS Symp., Vol. 2; p 7-11
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    Aircraft design for flight below the sonic boom speed limit (1974)
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    Publication Date: 2011-08-16
    Description: The avoidance of sonic booms places a constraint on aircraft design and can lead to unusual new configurations. From a comparison among several candidate designs, it is shown that an oblique-wing aircraft offers many advantages when structure, stability, flight efficiency, and airport noise are considered jointly.
    Keywords: AIRCRAFT
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    Determination of propulsion-system-induced forces and moments of a Mach 3 cruise aircraft (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: During the joint NASA/USAF flight research program with the YF-12 airplane, the Dutch roll damping was found to be much less during automatic inlet operation than during fixed inlet operation at Mach numbers greater than 2.5 and with the yaw stability augmentation system off. It was concluded that the significant reduction in Dutch roll damping was due to the forces and moments induced by the variable-geometry features of the inlet. Two stability-derivative extraction techniques were applied to the flight data; the recently developed Newton-Raphson technique and the time vector method. These techniques made it possible to determine the forces and moments generated by spike and bypass door movement.
    Keywords: AIRCRAFT
    Type: Parameter Estimation Tech. and Appl. in Aircraft Flight Testing; p 369-374
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    Estimation of structural parameters from dynamic test data (1974)
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    Publication Date: 2011-08-16
    Description: Parameters for a lumped linear model approximating a distributed elastic structure are determined from dynamic test data comprised of several mode shapes and frequencies. Measurement errors, nonlinear response, and nonmeasurable quantities such as mode slope components are accommodated. Some mass and stiffness parameters may be known accurately, whereas the remainder are to be estimated. The method entails minimizing a quadratic function of the difference between corresponding modes and frequencies of the theoretical model and the test specimen. This technique was applied to some actual vibration test data, and the special techniques that are required to overcome convergence problems are described.
    Keywords: AIRCRAFT
    Type: NASA. Flight Res. Center Parameter Estimation Tech. and Appl. in Aircraft Flight Testing; p 359-367
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    Estimation of elastic aircraft parameters using the maximum likelihood method (1974)
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    Publication Date: 2011-08-16
    Description: The application of the maximum likelihood method to estimate the aerodynamic parameters of elastic flight vehicles in a symmetric flight condition is discussed. In this application, particular attention is directed toward the center of mass, elastic deformation, and sensor equations of motion. It is shown that the two major computational problems to be overcome are the inversion of large-sized matrices and the time-wise integration of a large number of linear, ordinary, differential equations.
    Keywords: AIRCRAFT
    Type: NASA. Flight Res. Center Parameter Estimation Tech. and Appl. in Aircraft Flight Testing; p 337-358
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    Helicopter derivative identification from analytic models and flight test data (1974)
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    Publication Date: 2011-08-16
    Description: Recent results of stability derivative identification from helicopter analytic models and flight test data are presented. Six and nine degree-of-freedom (DOF) linear models are identified from an analytic nonlinear helicopter simulation using a least square technique. The identified models are compared with the convectional partial differentiation method for obtaining derivatives to form the basis for interpretation of derivatives identified from flight data. Six degree-of-freedom models are identified from CH-53A and CH-54B flight data, using an extended Kalman filter modified to process several maneuvers simultaneously. The a priori derivative estimate is obtained by optimal filtering of the data and then using a least square method. The results demonstrate that a six DOF identified model is sufficient to determine the low frequency modes of motion, but a nine DOF rotor/body model is necessary for proper representation of short-term response.
    Keywords: AIRCRAFT
    Type: NASA. Flight Res. Center Parameter Estimation Tech. and Appl. in Aircraft Flight Testing; p 175-186
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    Civil and scientific applications of the geoid (1974)
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    Publication Date: 2011-08-16
    Description: SEASAT-A can be used for determining the geoid to much higher accuracy on a world wide basis and in a relatively short time. Two basic objectives can be considered: (1) determination of the geoid to at least 1 meter. This accuracy will satisfy most geodetic requirements for applications purposes; and (2) determination of the geoid to better than 1-meter an oceanographic objective required for measurement of sea surface topography and sea slope, quasi-stationary departure from the geoid, ocean circulation, air and sea interaction, etc. The geodesy objective in this case will be to define a reference equipotential surface as a means by which the oceanographic requirements can be achieved.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA, Washington Seasat-A Sci. Contrib.; p 79-84
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    A unified technology plan for fatigue and fracture design (1974)
    In:  Other Sources
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    Publication Date: 2013-08-29
    Description: An integrated research program is proposed that seeks to improve the technology of designing against fatigue and fracture and to develop a computerized capability for assessing the adequacy of a given design. Both fatigue life prediction and damage tolerance considerations are incorporated. The research for each of these considerations is organized to account for material behavior, the effect of structural configurations, the cumulative effects of the operating loadings, and the effects of temperature and corrosion.
    Keywords: AIRCRAFT
    Type: RAE Fail-safe Aircraft Struct., Vol. 1; 22 p
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  • 57
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    Flight test of an automatic approach and landing concept for a simulated space shuttle represented by the NASA Convair 990 aircraft (1974)
    In:  CASI
    Details
    Publication Date: 2012-05-22
    Description: Unpowered automatic approaches and landings were conducted to study navigation, guidance, and control problems associated with terminal area, approach, and landing operation for the space shuttle. A Convair 990 aircraft was equipped with a digital flight-control computer connected to the aircraft control systems and displays. The flight tests evaluated, from 11,300 m to touchdown, the performance of a navigation and guidance concept that utilized blended radio/inertial navigation with VOR, DME, and ILS as the ground radio navigation aids. The results from 36 automatic approaches and landings are analyzed. Preliminary results indicate that this concept may provide sufficient accuracy that automatic landing of the unpowered shuttle orbiter can be accomplished on a conventional size runway.
    Keywords: AIRCRAFT
    Type: AGARD Advan. in Control Systems; 9 p
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    Integrated propulsion/energy transfer control systems for lift-fan V/STOL aircraft (1974)
    In:  CASI
    Details
    Publication Date: 2012-05-22
    Description: An integrated propulsion/control system for lift-fan transport aircraft is described. System behavior from full-scale experimental and piloted simulator investigations are reported. The lift-fan transport is a promising concept for short-to-medium haul civil transportation and for other missions. The lift-fan transport concept features high cruise airspeed, favorable ride qualities, small perceived noise footprints, high utilization, transportation system flexibility, and adaptability to VTOL, V/STOL, or STOL configurations. The lift-fan transport has high direct operating costs in comparison to conventional aircraft, primarily because of propulsion system and aircraft low-speed control system installation requirements. An integrated lift-fan propulsion system/aircraft low-speed control system that reduces total propulsion system and control system installation requirements is discussed.
    Keywords: AIRCRAFT
    Type: AGARD V(STOL Propulsion Systems; 8 p
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  • 59
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    Microwave profiling of snowpack free-water content (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: A microwave system is proposed to measure the amount of liquid-phase water in a snowpack operating in the range of 1 to 10 GHz. Attenuation of the beam between source and receivers is produced by the water in the snow. The relationships of frequency, distance, and volume percent of water are calculated for an assumed detector sensitivity, together with the estimated cost of a representative system. A laboratory test is described that shows the attenuation for snow at maximum wetness at 9.35 GHz. A configuration is proposed that involves a vertical tube containing microwave and radioactive sources and another vertical tube containing microwave and gamma-ray detectors, so that density and wetness profiles are obtained simultaneously over essentially the same path.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
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    Ejector-powered lift systems for V/STOL aircraft (1974)
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    Publication Date: 2011-08-16
    Description: The paper takes a brief look at powered lift from the point of view of the operator and the designer, considers application of an ejector-powered lift system to both STOL and VTOL aircraft, and describes some of the advantages of an ejector concept. Performance and noise characteristics of a simple ejector are described, and some comments are made regarding the Buffalo/Spey Augmentor-Wing proof-of-concept aircraft.
    Keywords: AIRCRAFT
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    Identification of M2/F3 stability and control derivatives from flight data containing gust effects (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: The application of the maximum likelihood identification technique to M2/F3 lifting body flight data containing wind gust effects is discussed. With the objective of this effort being the identification of the stability and control derivatives, it is shown first that the output error technique (or modified Newton-Raphson) fails to fit the recorded data accurately. The means of applying the maximum likelihood technique to this problem are then discussed and the results given which indicate an accurate fit to the data. The question of derivative signs opposite to the wind tunnel values is then addressed and the results of three techniques for dealing with this problem are presented. These techniques are a priori weighting, fixing parameter values, and rank deficient inverses.
    Keywords: AIRCRAFT
    Type: NASA. Flight Res. Center Parameter Estimation Tech. and Appl. in Aircraft Flight Testing; p 115-124
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    A survey of AFFDL parameter estimation efforts and future plans (1974)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: An overview is presented of the applications of parameter estimation methods to the following areas of interest at the Air Force Flight Dynamics Laboratory (AFFDL): (1) conventional stability and control parameter estimation of rigid aircraft; (2) extension to elastic aircraft; (3) extension to stall/spin aerodynamics of rigid aircraft with a nonlinear model; (4) application to the pilot model identification; and (5) correlation of wind tunnel, drop model and flight test data. Only well-documented algorithms are used with modification to the model as required for the specific application. The genesis of each problem and other background information are discussed which enumerate the algorithms and explain how this information is used to improve existing operational aircraft characteristics as well as specify design criteria for future USAF aerospace vehicles.
    Keywords: AIRCRAFT
    Type: NASA. Flight Res. Center Parameter Estimation Tech. and Appl. in Aircraft Flight Testing; p 19-38
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    An overview of parameter estimation techniques and applications in aircraft flight testing (1974)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: Parameter estimation is discussed as it applies to aircraft flight testing, and an overview of the symposium is presented. The evolution of techniques used in flight testing is reviewed briefly, and it is pointed out how the changing character of the aircraft tested and the availability of advanced data systems have promoted this evolution. Recent advances in optimal estimation theory have stimulated widespread interest and activity in parameter estimation. The framework of these advanced techniques is outlined to set the stage for subsequent papers. The session topics are introduced and related to the requirements of flight-test research.
    Keywords: AIRCRAFT
    Type: Parameter Estimation Tech. and Appl. in Aircraft Flight Testing; p 1-18
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  • 64
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    RPRVs - The first and future flights (1974)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: The merits of the RPRV (remotely piloted research vehicle) concept are discussed, along with its historical background and development culmination in the 3/8-scale F-15. The use of RPRVs is shown to be especially attractive when testing must be done at low cost, or in quick response to demand, or when hazardous testing must assure the safety of proceeding to manned vehicles.
    Keywords: AIRCRAFT
    Type: Astronautics and Aeronautics; 12; Apr. 197
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  • 65
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    The augmentor wing - Powered-lift STOL a proven concept (1974)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: A jet-STOL powered-lift aircraft has the ability to perform a relatively steep (7.5 deg) final approach at high power setting and a low speed. The DHC-5 Buffalo/Spey Augmentor-Wing research aircraft is the first machine of its kind to accomplish this performance. The aircraft uses an approach in which the cold bypass thrust is vectored by the augmentor flap. Aspects of aircraft reliability are discussed together with taxi trials, stalling characteristics, lateral directional control, single-engine operations, roll acceleration, and flight in turbulent conditions.
    Keywords: AIRCRAFT
    Type: Interavia; 29; Feb. 197
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  • 66
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    Long range view of materials research for civil transport aircraft (1974)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: The impact of various material technology advancements on the economics of civil transport aircraft is investigated. Benefits of advances in both airframe and engine materials are considered. Benefits are measured primarily by improvements in return on investment for an operator. Materials research and development programs which lead to the greatest benefits are assessed with regards to cost, risk, and commonality with other programs. Emphasis of the paper is on advanced technology subsonic/transonic transports (ATT type aircraft) since these are likely to be the next generation of commercial transports.
    Keywords: AIRCRAFT
    Type: SAMPE Quarterly; 5; Jan. 197
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  • 67
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    Design and flight experience with a digital fly-by-wire control system in an F-8 airplane (1974)
    In:  CASI
    Details
    Publication Date: 2012-05-22
    Description: A digital fly-by-wire flight control system was designed, built, and for the first time flown in an airplane. The system, which uses components from the Apollo guidance system, is installed in an F-8 airplane as the primary control system. A lunar module guidance computer is the central element in the three-axis, single-channel, multimode, digital control system. A triplex electrical analog system which provides unaugmented control of the airplane is the only backup to the digital system. Flight results showed highly successful system operation, although the trim update rate was inadequate for precise trim changes, causing minor concern. The use of a digital system to implement conventional control laws proved to be practical for flight. Logic functions coded as an integral part of the control laws were found to be advantageous. Although software verification required extensive effort, confidence in the software was achieved.
    Keywords: AIRCRAFT
    Type: AGARD Advan. in Control Systems; 10 p
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  • 68
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    Status of two studies on active control of aeroelastic response at NASA Langley Research Center (1974)
    In:  CASI
    Details
    Publication Date: 2012-05-22
    Description: The application of active control technology to the suppression of flutter was successfully demonstrated during two recent studies in the Langley transonic dynamics tunnel. The first study involved the implementation of an aerodynamic-energy criterion, using both leading- and trailing-edge controls, to suppress flutter of a simplified delta-wing model. Use of this technique resulted in an increase in the flutter dynamic pressure of approximately 12 percent for this model at a Mach number of 0.9. Analytical methods used to predict the open- and closed-loop behavior of the model are also discussed. The second study, which is a joint effort with the Air Force Flight Dynamics Laboratory, was conducted to establish the effect of active flutter suppression on a model of the Boeing B-52 Configured Vehicle (CCV). Some preliminary results of this study indicate significant improvements in the damping associated with the critical flutter mode.
    Keywords: AIRCRAFT
    Type: AGARD Active Control Systems for Load Alleviation, Flutter Suppression and Ride Control; p 23-48
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  • 69
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    Computer-aided design of control systems to meet many requirements (1974)
    In:  CASI
    Details
    Publication Date: 2012-05-22
    Description: A method is described for using nonlinear programing in the computer-aided design of airplane control systems. It is assumed that the quality of such systems depends on many criteria. These criteria are included in the constraints vector (instead of attempting to combine them into a single scalar criterion, as is usually done), and the design proceeds through a sequence of nonlinear programing solutions in which the designer varies the specification of sets of requirements levels. The method is applied to design of a lateral stability augmentation system (SAS) for a fighter airplane, in which the requirements vector is chosen from the official handling qualities specifications. Results are shown for several simple SAS configurations designed to obtain desirable handling qualities over all design flight conditions with minimum feedback gains. The choice of the final design for each case is not unique but depends on the designer's decision as to which achievable set of requirements levels represents the best for that system. Results indicate that it may be possible to design constant parameter SAS which can satisfy the most stringent handling qualities requirements for fighter airplanes in all flight conditions. The role of the designer as a decision maker, interacting with the computer program, is discussed. Advantages of this type of designer-computer interaction are emphasized. Desirable extensions of the method are indicated.
    Keywords: AIRCRAFT
    Type: AGARD Advan. in Control Systems; 7 p
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  • 70
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    Application of very long baseline interferometry to Astrometry and Geodesy: effects of frequency standard instability on accuracy (1974)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: The accuracy of geodetic and astrometric information obtained from very long baseline interferometry (VLBI) observations is dependent upon the stability of the frequency standard, or clock, used at each site of VLBI array. The sensitivities of two hydrogen maser frequency standards of different design to pressure, temperature, and magnetic field variations were measured; and, for one of the standards, sensitivity was found to be severe enough to degrade the information content of VLBI measurements. However, the effect on the geometric and astrometric information of such clock instabilities, with time scales of hours or greater, can be sharply reduced through the use of differencing techniques.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: Its Proc. of the Sixth Ann. Precise Time and Time Interval (PTTI) Planning Meeting; p 349-359
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  • 71
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    Hingeless rotor theory and experiment on vibration reduction by periodic variation of conventional controls (1974)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: The reduction of the n per rev. pitch-, roll- and vertical vibrations of an n-bladed rotor by n per rev. sinusoidal variations of the collective and cyclic controls is investigated. The numerical results presented refer to a four-bladed, 7.5-foot model and are based on frequency response tests conducted under an Army-sponsored research program. The following subjects are treated: extraction of the rotor transfer functions (.073R hub flapping and model thrust versus servo valve command, amplitude and phase), calculation of servo commands (volts) required to compensate .073R hub flapping (3P and 5P) and model thrust (4P), evaluation of the effect of the vibratory control inputs on blade loads, and theoretical prediction of the root flapbending moments generated by 0 to 5P perturbations of the feathering angle and rotor angle of attack. Five operating conditions are investigated covering advance ratios from approximately 0.2 to 0.85. The feasibility of vibration reduction by periodic variation on conventional controls is evaluated.
    Keywords: AIRCRAFT
    Type: NASA. Ames Res. Center Rotorcraft Dyn.; p 261-277
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  • 72
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    Engine/airframe interface dynamics experience (1974)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: Problems of engine/drive system torsional stability, engine and output shaft critical speeds, and engine vibration at helicopter rotor order frequencies are discussed, and test data and analyses presented. Also presented is a rotor/drive system dynamics problem not directly related to the engine.
    Keywords: AIRCRAFT
    Type: NASA. Ames Res. Center Rotorcraft Dyn.; p 249-260
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  • 73
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    Multicyclic jet-flap control for alleviation of helicopter blade stresses and fuselage vibration (1974)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: Results of wind tunnel tests of a 12 meter-diameter-rotor utilizing multicyclic jet-flap control deflection are presented. Analyses of these results are shown, and experimental transfer functions are determined by which optimal control vectors are developed. These vectors are calculated to eliminate specific harmonic bending stresses, minimize rms levels (a measure of the peak-to-peak stresses), or minimize vertical vibratory loads that would be transmitted to the fuselage. Although the specific results and the ideal control vectors presented are for a specific jet-flap driven rotor, the method employed for the analyses is applicable to similar investigations. A discussion of possible alternative methods of multicyclic control by mechanical flaps or nonpropulsive jet-flaps is presented.
    Keywords: AIRCRAFT
    Type: Its Rotorcraft Dyn.; p 233-238
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  • 74
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    Vertical-plane pendulum absorbers for minimizing helicopter vibratory loads (1974)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: The use of pendulum dynamic absorbers mounted on the blade root and operating in the vertical plane to minimize helicopter vibratory loads was discussed. A qualitative description was given of the concept of the dynamic absorbers and some results of analytical studies showing the degree of reduction in vibratory loads attainable are presented. Operational experience of vertical plane dynamic absorbers on the OH-6A helicopter is also discussed.
    Keywords: AIRCRAFT
    Type: NASA. Ames Res. Center Rotorcraft Dyn.; p 219-222
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  • 75
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    Hub moment springs on two-bladed teetering rotors (1974)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: Two-bladed teetering rotors with elastic flapping hinge restraint are shown to be suitable for zero-g flight. The alternating moment component introduced into the fuselage by the hinge spring can be balanced about the aircraft center of gravity by alternating hub shears. Such shears can be produced in proper magnitude, frequency, and phase by additional underslinging of the hub and by judicious choice of the location of the first inplane cantilevered natural frequency. Trends of theoretical results agree with test results from a small scale model and a modified OH-58A helicopter.
    Keywords: AIRCRAFT
    Type: NASA. Ames Res. Center Rotorcraft Dyn.; p 199-204
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  • 76
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    Evaluation of a stall-flutter spring-damper pushrod in the rotating control system of a CH-54B helicopter (1974)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: Results of a design and flight test program conducted to define the effect of rotating pushrod damping on stall-flutter induced control loads are presented. The CH-54B helicopter was chosen as the test aircraft because it exhibited stall induced control loads. Damping was introduced into the CH-54B control system by replacing the standard pushrod with spring-damper assemblies. Design features of the spring-damper are described and the results of a dynamic analysis are shown which define the pushrod stiffness and damping requirements. Flight test measurements taken at 47,000 lb gross weight with and without the damper are presented. The results indicate that the spring-damper pushrods reduced high frequency, stall-induced rotating control loads by almost 50%. Fixed system control loads were reduced by 40%. Handling qualities in stall were unchanged, as expected.
    Keywords: AIRCRAFT
    Type: NASA. Ames Res. Center Rotorcraft Dyn.; p 223-232
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  • 77
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    Comparison of flight data and analysis for hingeless rotor regressive inplane mode stability (1974)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: Analytical and experimental data obtained during the development of the AH-56A covering stability of the regressive inplane mode, including coupling with other modes such as body and rotor plunge are reported. Data were obtained on two distinctly different control systems; both gyro controlled, but one with feathering moment feedback and the other with direct flapping feedback. A review was made of analytical procedures employed in investigating the stability of this mode and a comparison was made of the analytical and experimental data. The effect of certain parameters including blade droop, sweep, delta 3, alpha 1, vehicle roll inertia, inplane frequency, and rpm and forward speed on the mode were also reviewed. It was shown that the stability of this mode is treatable by analysis and that adequate stability is achievable without recourse to auxiliary inplane damping devices.
    Keywords: AIRCRAFT
    Type: NASA. Ames Res. Center Rotorcraft Dyn.; p 185-197
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  • 78
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    Rotor aeroelastic stability coupled with helicopter body motion (1974)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: A 5.5-foot-diameter, soft-in-plane, hingeless-rotor system was tested on a gimbal which allowed the helicopter rigid-body pitch and roll motions. Coupled rotor/airframe aeroelastic stability boundaries were explored and the modal damping ratios were measured. The time histories were correlated with analysis with excellent agreement. The effects of forward speed and some rotor design parameters on the coupled rotor/airframe stability were explored both by model and analysis. Some physical insights into the coupled stability phenomenon are suggested.
    Keywords: AIRCRAFT
    Type: NASA. Ames Res. Center Rotorcraft Dyn.; p 137-146
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  • 79
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    An application of Floquet theory to prediction of mechanical instability (1974)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: The problem of helicopter mechanical instability is considered for the case where one blade damper is inoperative, and it is shown that if the hub is considered to be nonisotropic, the equations of motion have periodic coefficients which cannot be eliminated. The Floquet transition matrix method is shown to be an effective way of dealing with the nonisotropic hub and nonisotropic rotor situation. Time history calculations are examined and shown to be inferior to the Floquet technique for determining system stability. It is shown that instabilities which occur when one blade damper is inoperative may consist of nearly pure blade motion or they may be similar to the classical mechanical instability.
    Keywords: AIRCRAFT
    Type: NASA. Ames Res. Center Rotorcraft Dyn.; p 147-158
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  • 80
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    Application to rotary wings of a simplified aerodynamic lifting surface theory for unsteady compressible flow (1974)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: A general method of predicting airloads is applied to helicopter rotor blades on a full three-dimensional basis using the general theory developed for a rotor blade at the psi = pi/2 position where flutter is most likely to occur. Calculations of aerodynamic coefficients for use in flutter analysis are made for forward and hovering flight with low inflow. The results are compared with values given by two-dimensional strip theory for a rigid rotor hinged at its root. The comparisons indicate the inadequacies of strip theory for airload prediction. One important conclusion drawn from this study is that the curved wake has a substantial effect on the chordwise load distribution.
    Keywords: AIRCRAFT
    Type: NASA. Ames Res. Center Rotorcraft Dyn.; p 127-135
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  • 81
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    The effect of cyclic feathering motions on dynamic rotor loads (1974)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: The dynamic loads of a helicopter rotor in forward flight are influenced significantly by the geometric pitch angles between the structural axes of the hub and blade sections and the plane of rotation. The analytical study presented includes elastic coupling between inplane and out-of-plane deflections as a function of geometric pitch between the plane of rotation and the principal axes of inertia of each blade. The numerical evaluation is based on a transient analysis using lumped masses and elastic substructure techniques. A comparison of cases with and without cyclic feathering motion shows the effect on computed dynamic rotor loads.
    Keywords: AIRCRAFT
    Type: NASA. Ames Res. Center Rotorcraft Dyn.; p 107-114
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  • 82
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    Helicopter gust response characteristics including unsteady aerodynamic stall effects (1974)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: The results of an analytical study to evaluate the general response characteristics of a helicopter subjected to various types of discrete gust encounters are presented. The analysis employed was a nonlinear coupled, multi-blade rotorfuselage analysis including the effects of blade flexibility and unsteady aerodynamic stall. Only the controls-fixed response of the basic aircraft without any aircraft stability augmentation was considered. A discussion of the basic differences between gust sensitivity of fixed and rotary wing aircraft is presented. The effects of several rotor configuration and aircraft operating parameters on initial gust-induced load factor and blade vibratory stress and pushrod loads are discussed.
    Keywords: AIRCRAFT
    Type: NASA. Ames Res. Center Rotorcraft Dyn.; p 91-100
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  • 83
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    Flap-lag dynamics of hingeless helicopter blades at moderate and high advance ratios (1974)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: Equations for large amplitude coupled flaplag motion of a hingeless elastic helicopter blade in forward flight are derived. Only a torsionally rigid blade exicted by quasi-steady aerodynamic loads is considered. The effects of reversed flow together with some new terms due to forward flight are included. Using Galerkin's method the spatial dependence is eliminated and the equations are linearized about a suitable equilibrium position. The resulting system of equations is solved using multivariable Floquet-Liapunov theory, and the transition matrix at the end of the period is evaluated by two separate methods. Results illustrating the effects of forward flight and various important blade parameters on the stability boundaries are presented.
    Keywords: AIRCRAFT
    Type: NASA. Ames Res. Center Rotorcraft Dyn.; p 55-66
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  • 84
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    Some approximations to the flapping stability of helicopter rotors (1974)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: The flapping equation for a helicopter in forward flight are reported which have coefficients that are periodic in time, and this effect complicates the calculation of stability. A constant coefficient approximation which will allow the use of all the well known methods for analyzing constant coefficient equations are presented. The flapping equation is first transformed into the nonrotating coordinate frame, where some of the periodic coefficients are transformed into constant terms. The constant coefficient approximation is then made by using time averaged coefficients in the nonrotating frame. Stability calculations based on the approximation are compared to results from a theory which correctly includes all of the periodicity. The comparison indicates that the approximation is reasonably accurate at advance ratios up to 0.5.
    Keywords: AIRCRAFT
    Type: Its Rotorcraft Dyn.; p 45-53
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  • 85
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    Dynamic analysis of multi-degree-of-freedom systems using phasing matrices (1974)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: A mathematical technique is presented for improved analysis of a wide class of dynamic and aeroelastic systems characterized by several degrees-of-freedom. The technique enables greater utilization of the usual eigensolution obtained from the system dynamic equations by systematizing the identification of destabilizing and/or stiffening forces. Included, as illustrative examples of the use of the technique, are analyses of a helicopter rotor blade for bending-torsion divergence and flutter and for pitch-lag/flap instability.
    Keywords: AIRCRAFT
    Type: NASA. Ames Res. Center Rotorcraft Dyn.; p 35-43
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  • 86
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    Computer experiments on periodic systems identification using rotor blade transient flapping-torsion responses at high advance ratio (1974)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: Systems identification methods have recently been applied to rotorcraft to estimate stability derivatives from transient flight control response data. While these applications assumed a linear constant coefficient representation of the rotorcraft, the computer experiments described in this paper used transient responses in flap-bending and torsion of a rotor blade at high advance ratio which is a rapidly time varying periodic system.
    Keywords: AIRCRAFT
    Type: NASA. Ames Res. Center Rotorcraft Dyn.; p 25-34
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  • 87
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    Hingeless rotor frequency response with unsteady inflow (1974)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: Hingeless rotor frequency response calculations are obtained by applying a generalized harmonic balance to the elastic blade flapping equations. Nonuniform, unsteady induced flow effects are included by assuming a simple three-degree-of-freedom description of the rotor wake. Results obtained by using various models of elastic blade bending and induced flow are compared with experimental data obtained from a 7.5-ft diameter wind tunnel model at advance ratios from 0.0 to 0.6. It is shown that the blade elasticity and nonuniform, unsteady induced flow can have a significant effect on the transient response characteristics of rotor systems.
    Keywords: AIRCRAFT
    Type: NASA. Ames Res. Center Rotorcraft Dyn.; p 1-12
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  • 88
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    Data resolution versus forestry classification (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: There are no author-identified significant results in this report.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: E80-10189 , NASA-CR-160610
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  • 89
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    HFL-10 lifting body flight control system characteristics and operational experience (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A flight evaluation was made of the mechanical hydraulic flight control system and the electrohydraulic stability augmentation system installed in the HL-10 lifting body research vehicle. Flight tests performed in the speed range from landing to a Mach number of 1.86 and the altitude range from 697 meters (2300 feet) to 27,550 meters (90,300 feet) were supplemented by ground tests to identify and correct structural resonance and limit-cycle problems. Severe limit-cycle and control sensitivity problems were encountered during the first flight. Stability augmentation system structural resonance electronic filters were modified to correct the limit-cycle problem. Several changes were made to control stick gearing to solve the control sensitivity problem. Satisfactory controllability was achieved by using a nonlinear system. A limit-cycle problem due to hydraulic fluid contamination was encountered during the first powered flight, but the problem did not recur after preflight operations were improved.
    Keywords: AIRCRAFT
    Type: NASA-TM-X-2956 , H-704
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  • 90
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    Analysis and calculation of lightning-induced voltages in aircraft electrical circuits (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Techniques to calculate the transfer functions relating lightning-induced voltages in aircraft electrical circuits to aircraft physical characteristics and lightning current parameters are discussed. The analytical work was carried out concurrently with an experimental program of measurements of lightning-induced voltages in the electrical circuits of an F89-J aircraft. A computer program, ETCAL, developed earlier to calculate resistive and inductive transfer functions is refined to account for skin effect, providing results more valid over a wider range of lightning waveshapes than formerly possible. A computer program, WING, is derived to calculate the resistive and inductive transfer functions between a basic aircraft wing and a circuit conductor inside it. Good agreement is obtained between transfer inductances calculated by WING and those reduced from measured data by ETCAL. This computer program shows promise of expansion to permit eventual calculation of potential lightning-induced voltages in electrical circuits of complete aircraft in the design stage.
    Keywords: AIRCRAFT
    Type: NASA-CR-2349 , SRD-72-066
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  • 91
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    Developmental design, fabrication, and test of acoustic suppressors for fans of high bypass turbofan engines (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: An analysis procedure was developed for design of acoustically treated nacelles for high bypass turbofan engines. The plan was applied to the conceptual design of a nacelle for the quiet engine typical of a 707/DC-8 airplane installation. The resultant design was modified to a test nacelle design for the NASA Lewis quiet fan. The acoustic design goal was a 10 db reduction in effective perceived fan noise levels during takoff and approach. Detailed nacelle designs were subsequently developed for both the quiet engine and the quiet fan. The acoustic design goal for each nacelle was 15 db reductions in perceived fan noise levels from the inlet and fan duct. Acoustically treated nacelles were fabricated for the quiet engine and quiet fan for testing. Performance of selected inlet and fan duct lining configurations was experimentally evaluated in a flow duct. Results of the tests show that the linings perform as designed.
    Keywords: AIRCRAFT
    Type: NASA-CR-2338 , D3-8952
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  • 92
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    Flight experience with the decelerating noise abatement approach (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The noise of older aircraft can be reduced in two principal ways: retrofitting the aircraft with a quiet propulsion system, and changing the flight operational procedures used in flying the aircraft. The former approach has already proved to be expensive, time consuming, and difficult to implement even though low-noise propulsion system technology exists. The latter method seems to hold promise of being less expensive and easier to implement. One operational technique which might reduce the noise beneath the landing approach path is the decelerating approach. This technique requires intercepting the 3 deg approach path at a relatively high speed with the aircraft in the cruise configuration, then reducing the thrust to idle and allowing the aircraft to decelerate along the 3 deg approach path. As the appropriate airspeed is achieved, the landing flaps and landing gear are deployed for a normal flare and landing. Because the engines, which are the predominant noise source on landing approach, are at idle thrust, a significant reduction in the noise beneath the approach path should be realized.
    Keywords: AIRCRAFT
    Type: NASA-TM-X-56020
    Format: application/pdf
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  • 93
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    Land use mapping in Erie County, Pennsylvania: A pilot study (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The author has identified the following significant results. A pilot study was conducted to determine the feasibility of mapping land use in the Great Lakes Basin area utilizing ERTS-1 data. Small streams were clearly defined by the presence of trees along their length in predominantly agricultural country. Field patterns were easily differentiated from forested areas; dairy and beef farms were differentiated from other farmlands, but no attempt was made to identify crops. Large railroad lines and major highway systems were identified. The city of Erie and several smaller towns were identified, as well as residential areas between these towns, and docks along the shoreline in Erie. Marshes, forests, and beaches within Presque Isle State Park were correctly identified, using the DCLUS program. Bay water was differentiated from lake water, with a small amount of misclassification.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: E75-10401 , NASA-CR-143394 , ORSER-SSEL-TR-24-74
    Format: application/pdf
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  • 94
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    TERSSE: Definition of the Total Earth Resources System for the Shuttle Era. Volume 5: Detailed system requirements: Two case studies (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Major resource management missions to be performed by the TERSSE are examined in order to develop an understanding of the form and function of a system designed to perform an operational mission. Factors discussed include: resource manager (user) functions, methods of performing their function, the information flows and information requirements embodied in their function, and the characteristics of the observation system which assists in the management of the resource involved. The missions selected for study are: world crop survey and land resources management. These missions are found to represent opposite ends of the TERSSE spectrum and to support the conclusion that different missions require different systems and must be analyzed in detail to permit proper system development decisions.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA-CR-141771
    Format: application/pdf
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  • 95
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    Skylab 4 photographic index and scene identification (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A quick reference guide to the photographic imagery obtained on Skylab 4 is presented. Place names and descriptors used give sufficient information to identify frames for discussion purposes and are not intended to be used for ground nadir or geographic coverage purposes.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA-TM-X-72440 , JL12-603
    Format: application/pdf
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  • 96
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    Flight test data for a Cessna Cardinal (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The results of a flight test analysis of the performance of a standard Cessna 177B Cardinal airplane are presented. The airplane was fully instrumented to obtain steady state performance, stick-fixed dynamic stability characteristics, and roll response data. Results obtained include graphs of C sub L versus alpha, C sub D versus C sub L, and speed-power relationships. Dynamic data include Phugoid and Dutch characteristics, and roll response characteristics.
    Keywords: AIRCRAFT
    Type: NASA-CR-2337 , FRL-72-001
    Format: application/pdf
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  • 97
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    Analytical design and simulation evaluation of an approach flight director system for a jet STOL aircraft (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A program was undertaken to develop design criteria and operational procedures for STOL transport aircraft. As part of that program, a series of flight tests shall be performed in an Augmentor Wing Jet STOL Aircraft. In preparation for the flight test programs, an analytical study was conducted to gain an understanding of the characteristics of the vehicle for manual control, to assess the relative merits of the variety of manual control techniques available with attitude and thrust vector controllers, and to determine what improvements can be made over manual control of the bare airframe by providing the pilot with suitable command guidance information and by augmentation of the bare airframe dynamics. The objective of the study is to apply closed-loop pilot/vehicle analysis techniques to the analysis of manual flight control of powered-lift STOL aircraft in the landing approach and to the design and experimental verification of an advanced flight director display.
    Keywords: AIRCRAFT
    Type: NASA-CR-114697 , STI-TR-1015-1
    Format: application/pdf
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  • 98
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    Development of acoustically lined ejector technology for multitube jet noise suppressor nozzles by model and engine tests over a wide range of jet pressure ratios and temperatures (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: An experimental program comprising model nozzle and full-scale engine tests was undertaken to acquire parametric data for acoustically lined ejectors applied to primary jet noise suppression. Ejector lining design technology and acoustical scaling of lined ejector configurations were the major objectives. Ground static tests were run with a J-75 turbojet engine fitted with a 37-tube, area ratio 3.3 suppressor nozzle and two lengths of ejector shroud (L/D = 1 and 2). Seven ejector lining configurations were tested over the engine pressure ratio range of 1.40 to 2.40 with corresponding jet velocities between 305 and 610 M/sec. One-fourth scale model nozzles were tested over a pressure ratio range of 1.40 to 4.0 with jet total temperatures between ambient and 1088 K. Scaling of multielement nozzle ejector configurations was also studied using a single element of the nozzle array with identical ejector lengths and lining materials. Acoustic far field and near field data together with nozzle thrust performance and jet aerodynamic flow profiles are presented.
    Keywords: AIRCRAFT
    Type: NASA-CR-2382 , D6-60226
    Format: application/pdf
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  • 99
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    Direct measurement of sound sources in air jets using the crossed beam correlation technique (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Properties of density fluctuations were measured in the turbulent regions of a 2.54 cm air jet, at M = 0.7, 1.0 and 1.94. After calibration tests, it was found that the absorption of infrared radiation at 4.3 microns by the naturally present quantities of carbon-dioxide in air was directly proportional to the air density if a sufficiently wide bandpass (0.08 microns) was used. Moreover, regions of the band could be selected that adequately discriminated against temperature variations. The cross-correlation of two such beams intersecting in the jet gave a measure of the local properties at the intersection point. A derivation is presented relating the local density correlation function to the self and shear generated noise in the far field of the jet. The measured correlations are used to predict the axial distribution of source strengths and the spectrum of noise due to a unit volume of turbulence.
    Keywords: AIRCRAFT
    Type: AGARD Noise Mech.; 16 p
    Format: text
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  • 100
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    A Flight Investigation of the STOL Characteristics of an Augmented Jet Flap STOL Research Aircraft (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The flight test program objectives are: (1) To determine the in-flight aerodynamic, performance, and handling qualities of a jet STOL aircraft incorporating the augmented jet flap concept; (2) to compare the results obtained in flight with characteristics predicted from wind tunnel and simulator test results; (3) to contribute to the development of criteria for design and operation of jet STOL transport aircraft; and (4) to provide a jet STOL transport aircraft for STOL systems research and development. Results obtained during the first 8 months of proof-of-concept flight testing of the aircraft in STOL configurations are reported. Included are a brief description of the aircraft, fan-jet engines, and systems; a discussion of the aerodynamic, stability and control, and STOL performance; and pilot opinion of the handling qualities and operational characteristics.
    Keywords: AIRCRAFT
    Type: NASA-TM-X-62334 , A-5418
    Format: application/pdf
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