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Telesystems Conference, 1991. Proceedings. Vol.1., NTC '91., National

Date 26-27 March 1991

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  • NTC '91. National Telesystems Conference Proceedings. Vol.1. (Cat. No.91CH3010-6)

    Publication Year: 1991
    Request permission for commercial reuse | PDF file iconPDF (37 KB)
    Freely Available from IEEE
  • Digital aircraft flight controls design using output feedback

    Publication Year: 1991, Page(s):13 - 18
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (392 KB)

    An approach that uses linear quadratic output feedback techniques is given for designing digital control systems of specified structure for shaping the closed-loop step response. This approach results in digital controllers that take advantage of the wealth of experience in aircraft controls design. The correct initial conditions for determining the output-feedback gains are not uniformly distribu... View full abstract»

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  • Phased array noise considerations

    Publication Year: 1991, Page(s):199 - 203
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (364 KB)

    Several concepts and formulae are presented that are useful in the examination of the signal-to-noise performance of phased array antennas with dissimilar signal paths or subarray sizes. It is demonstrated that, in most such cases, aperture illumination efficiency remains an accurate indication of array antenna noise performance View full abstract»

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  • Decomposition of the radar target scattering matrix with application to high resolution target imaging

    Publication Year: 1991, Page(s):77 - 82
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (452 KB)

    The basic theory of polarimetric radar and various decomposition theories are briefly reviewed. A novel decomposition of the scattering matrix is then presented with special reference to high-resolution imaging. By decomposing the scattering matrix into three different components, it is possible to resolve different types of scatterers even if they are within the same resolution cell of the image.... View full abstract»

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  • An alternate optimal formulation for robust eigenstructure assignment

    Publication Year: 1991, Page(s):7 - 11
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (344 KB)

    An alternative eigenstructure assignment formulation which has inherent advantages over a previous formulation is introduced. A highly nonlinear performance index has been replaced by a quadratic one at the expense of an increase in the nonlinearity and number of constraints. Overall, the present formulation presents a significantly simpler problem from a numerical optimization viewpoint. Addition... View full abstract»

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  • The Space Station Freedom special purpose dexterous manipulator (SPDM)

    Publication Year: 1991, Page(s):371 - 376
    Cited by:  Papers (1)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (488 KB)

    Canada is contributing a robotic mobile servicing system (MSS) to the Space Station Freedom, which will play an integral role in the assembly of Freedom and its operation. One element of the MSS, the special purpose dexterous manipulator, is a dual arm robot having the capability to perform dexterous tasks. The SPDM will replace much of the extravehicular astronaut activity which would otherwise b... View full abstract»

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  • Satellite ocean color data for studying oceanic biogeochemical cycles

    Publication Year: 1991, Page(s):283 - 287
    Cited by:  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (436 KB)

    The ocean color mission, a spaceflight mission designed to provide daily, high precision, moderate resolution, multispectral visible observations of global ocean radiance for research in biogeochemical processes, climate change, and oceanography, is described. Data delivery will commence in autumn 1993. Data will be taken from an ocean color instrument in a near noon sun-synchronous orbit. Local, ... View full abstract»

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  • JEMRMS system design and development status

    Publication Year: 1991, Page(s):391 - 395
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (344 KB)

    The authors present an overview of the baseline configuration of the JEMRMS (Japanese Experiment Module Remote Manipulator System) and summarize the status of the system and element development tests. JEMRMS has mother-daughter type manipulators: a 10 m long mother arm (main arm) and a 2 m-long daughter arm (small fine arm). The main arm (MA) provides that capability of transferring, retrieving, a... View full abstract»

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  • DSCS III Receive Multiple Beam Antenna performance improvement

    Publication Year: 1991, Page(s):147 - 150
    Cited by:  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (248 KB)

    In an effort to cope with the increasing demand of services on the Defense Satellite Communications System (DSCS) and more stringent ECCM (electronic counter-countermeasures) requirements, the performance limitations on the DSCS III Receive Multiple Beam Antenna (RMBA) imposed by random and systematic perturbations have been addressed. The concept of VPSFT (variable phase shifter fine tuning) clos... View full abstract»

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  • Active-element, phased-array radar: affordable performance for the 1990s

    Publication Year: 1991, Page(s):193 - 197
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (372 KB)

    Active-element, electronically scanned, phased-array (AESA) radars have been shown to offer unique solutions for future airborne weapons systems. Flight demonstrations have validated AESA technologies and have clearly shown the advantages of AESA radars. These technologies are the product of research programs carried out over the past 25 years that led to airborne demonstration of AESA radars in 1... View full abstract»

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  • Control of an omni-directional robotic vehicle with Mecanum wheels

    Publication Year: 1991, Page(s):323 - 328
    Cited by:  Papers (16)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (376 KB)

    The authors explore three aspects of the Mecanum wheeled vehicles, the ability to maneuver in congested spaces, the kinematics of wheel design, and considerations for wheel loading and traction. It is shown how omni-directional capability greatly reduces the amount of area and time required for maneuvers, and how the Mecanum wheel in particular reduces time because of the absence of singularities.... View full abstract»

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  • Autonomous Landing Guidance concept validation

    Publication Year: 1991, Page(s):37 - 46
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (676 KB)

    The Autonomous Landing Guidance system is intended to provide pilots visibility and landing guidance at night regardless of the weather and without the need for standard, ground-based navigation aids. The basic system concept, employing precision-updated INS (inertial navigation system) guidance with multispectral imaging on a heads-up display (HUD), has been validated and system demonstration dat... View full abstract»

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  • Optimal polarimetric processing for enhanced target detection

    Publication Year: 1991, Page(s):69 - 75
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (576 KB)

    The results of a study of several polarimetric target detection algorithms are presented. The study concerns the Lincoln Laboratory millimeter-wave SAR sensor, a fully polarimetric, 35 GHz synthetic-aperture radar. Fully polarimetric measurements (HH, HV, VV) are processed into intensity imagery using adaptive and nonadaptive polarimetric whitening filters (PWFs), and the amount of speckle reducti... View full abstract»

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  • Neural network based control system design of an advanced fighter aircraft

    Publication Year: 1991, Page(s):1 - 6
    Cited by:  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (452 KB)

    The author demonstrates the application of neural network technology to optimal scheduling of control gains in real-time flight control systems commonly used in the real-time control of an advanced fighter aircraft and high-performance aerospace vehicles where a priori target outputs are not known, and must be generated in real-time. A learning algorithm and an appropriate performance model have b... View full abstract»

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  • Effects of obscurant materials on millimeter wave seekers

    Publication Year: 1991, Page(s):367 - 370
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (392 KB)

    Millimeter-wave radar seeker functions for detecting, classifying, identifying, and tracking ground targets are described. The adverse effects of both naturally occurring and man-made obscurant material are discussed. Obscurants considered include clear air components, fog, rain, frozen hydrometeors, and specially designed smokes. The phenomenological characteristics that affect radar performance ... View full abstract»

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  • Systems considerations for large percent-bandwidth radar

    Publication Year: 1991, Page(s):133 - 137
    Cited by:  Papers (1)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (468 KB)

    Several new terms denoting new types of radar waveforms (e.g. impulse, nonsinusoidal, monocycle, baseband, and ultra-wideband) have recently emerged. The author attempts to set all of these waveform types in a consistent perspective and to assess the potential performance available from each. The perspective chosen for the waveform cataloging process is the measure of carrier cycles per pulse, or,... View full abstract»

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  • Imaging of a compact range using autoregressive spectral estimation

    Publication Year: 1991, Page(s):177 - 182
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (460 KB)

    An estimation technique based on the autoregressive (AR) modeling of field probe data is used to locate and quantify spurious signals in a compact range. In this technique, the probe aperture is divided into a number of overlapping subapertures such that the far-field criterion for each subaperture is satisfied. Then the subaperture data are modeled as an AR process, and the AR parameters are deri... View full abstract»

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  • The Landsat-6 satellite: an overview

    Publication Year: 1991, Page(s):277 - 282
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (572 KB)

    Landsat 6 (L6), a remote land sensing satellite, is scheduled to be launched into a 705 km, circular, sun-synchronous orbit by a Titan-II booster in mid 1992. The L6 satellite has been designed to provide 30 m spatial resolution multispectral image data continuity via an enhanced thematic mapper (ETM) sensor which includes a panchromatic band with 15 m spatial resolution. A brief background descri... View full abstract»

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  • Flight Telerobotic Servicer: the design and evolution of a dexterous space telerobot

    Publication Year: 1991, Page(s):385 - 390
    Cited by:  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (524 KB)

    The Flight Telerobotic Servicer (FTS) Project is developing an advanced telerobotic system to assist in and reduce the crew extravehicular activity for Space Station Freedom. The FTS will provide a telerobotic capability to the Freedom Station in the early assembly phases of the program and will be employed for assembly, maintenance, and inspection applications throughout the lifetime of the Space... View full abstract»

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  • Remote control of a telerobotic underwater vehicle via satellite

    Publication Year: 1991, Page(s):331 - 336
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (364 KB)

    The authors describe remote operation of a telerobotic underwater vehicle system. As part of an educational effort called the JASON Project, students from a network of downlink sites across North America piloted the vehicle in the course of an archeological expedition in Lake Ontario. The vehicle, control system, telecommunications, and remote control station technology are described, and operatio... View full abstract»

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  • Lightweight beamforming networks

    Publication Year: 1991, Page(s):143 - 146
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (224 KB)

    Lightweight BFN (beamforming network) implementation based on a hybrid mode technology is described and shown to provide dramatic weight and size reduction relative to waveguide-implemented designs. The hybrid mode technology refers to an integration of microstrip and guided wave media. The basic control element is a ferrite phaser which is significantly reduced in size and weight and which incorp... View full abstract»

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  • Design of a lightweight broadband element for an airborne phased array

    Publication Year: 1991, Page(s):187 - 190
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (392 KB)

    A lightweight broadband phased array element was designed and manufactured using microstrip patch technology for an airborne telemetry antenna application. The electrical requirements of the element included nearly a 10 percent bandwidth, dual orthogonal linear polarization, ±60° azimuth coverage, and low mismatch loss. In addition to the electrical requirements, the lightweight element... View full abstract»

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  • Pulsed polarimetric millimeter-wave radars that utilize extended interaction amplifier and oscillator tubes

    Publication Year: 1991, Page(s):343 - 346
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (216 KB)

    The University of Massachusetts has developed two high-power portable polarimetric radars operating at 95 and 225 GHz. The 95 GHz polarimeter employs an extended-interaction klystron amplifier capable of 1500 W peak power output. The system is configured to measure the complex scattering matrix of a target by transmitting a pair of orthogonally polarized pulses in rapid succession. A noncoherent 2... View full abstract»

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  • Development of rapid runway repair (RRR) telerobotic construction equipment

    Publication Year: 1991, Page(s):321 - 322
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (192 KB)

    The nature of the RRR mission requires that construction/repair equipment operators be placed in positions that could result in death or bodily harm to the operators. Additionally, the possibility of early loss of trained equipment operators leads to the problem of poor machine performance and consequent unacceptable increases in runway repair times. To overcome these problems the US Air Force is ... View full abstract»

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  • Time-optimal control application for an exoatmospheric interceptor

    Publication Year: 1991, Page(s):31 - 36
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (260 KB)

    The optimum control solution for the capture of an exoatmospheric interceptor's attitude and rate errors is derived. A practical application of the method is investigated by considering the timing constraints imposed by the pulsewidth modulation scheme, and, as a result, timing logic for the thruster firings is derived. The concept is verified by comparing a three-pulse capture with the optimum tw... View full abstract»

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