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Aerospace and Electronic Systems, IEEE Transactions on

Issue 3 • Date May 1988

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Displaying Results 1 - 13 of 13
  • Clutter suppression using recursive and nonrecursive MTI filters

    Publication Year: 1988 , Page(s): 210 - 217
    Cited by:  Papers (5)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (424 KB)  

    The author calculates the effectiveness of clutter suppression of a moving-target-indicator (MTI) filter in tandem with a fast-Fourier-transform (FFT) Doppler filter bank, taking into account the transient response of the MTI filter. Both recursive and nonrecursive filters are considered. The analysis is extended to the high-pulse-repetition-frequency (PRF) case with clutter fold over. The results can be used to select key design parameters, including the MTI filter, the window size, and the initial transient segment to be discarded. Numerical examples are included View full abstract»

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  • Nth-order dynamics target observability from angle measurements

    Publication Year: 1988 , Page(s): 305 - 308
    Cited by:  Papers (48)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (224 KB)  

    Necessary and sufficient conditions are presented for the observability of the target's Nth-order dynamics, given direction measurements. The derivations are extremely simple and do not require the examination of an observability matrix or nonlinear differential equations. Previously published observability requirements for the first-order dynamics are shown to be necessary but not sufficient View full abstract»

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  • Maximum a posteriori approach to object recognition with distributed sensors

    Publication Year: 1988 , Page(s): 309 - 313
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (232 KB)  

    The maximum a posteriori (MAP) estimation concept is applied to the problem of object recognition with several distributed sensors. It is shown that in binary object recognition the MAP object recognition also minimizes the mean-square error. Simulation results show that the performance of the MAP object recognition is, in general, at least as good as the best performance by the sensors used View full abstract»

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  • An adaptive controller for current-fed induction motor

    Publication Year: 1988 , Page(s): 250 - 262
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (704 KB)  

    A model reference speed adaptive controller for a current-fed induction motor drive is proposed. It uses a proportional-plus-integral (PI) adaptation to satisfy the hyperstability condition for taking care of the load and machine parameter changes of the drive. The available information on the states and output of the reference model as well as the plant output are all that are required for the control; no explicit parameter identification is needed. The controller can be designed by using a reduced reference model to simplify the design without much degradation of the performance, so that it is relatively easy to implement practically View full abstract»

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  • Strip mode processing of spotlight aperture radar data

    Publication Year: 1988 , Page(s): 225 - 230
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (472 KB)  

    The author shows how to process deramped (e.g., typical spotlight mode) synthetic-aperture-radar (SAR) data using mode processors, with no restrictions on antenna pointing. The basis of the approach is that although the deramped data does not contain a spatially invariant two-dimensional response to a point target, the range-compressed deramped data does. Range compression of the deramped data is performed simply by Fourier transforming each range line. The method greatly increases the flexibility of current strip mode processors by extending their domain to a previously unsuitable class of data View full abstract»

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  • Modeling and simulation of spacecraft power systems

    Publication Year: 1988 , Page(s): 295 - 304
    Cited by:  Papers (24)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (536 KB)  

    Modeling of a complete spacecraft power processing system is presented, using the Boeing EASYS software. Component models are developed, and several system models including a solar array switching system, a partially shunted solar system, and cosmic background explorer (COBE) system are simulated. The modes of operation of the power system, such as shunt mode, battery-charge mode, and battery-discharge mode, are simulated for a complete orbit cycle View full abstract»

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  • Tracking multiple targets with correlated measurements and maneuvers

    Publication Year: 1988 , Page(s): 313 - 315
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (200 KB)  

    The problem of tracking N targets with correlation in both measurement and maneuver statistics is solved by transforming to a coordinate frame in which the N targets are decoupled. For the case of N identical targets, the decoupling is shown to coincide with a transformation to a set of nested center-of-mass coordinates. Absolute and differential tracking accuracies are compared with suboptimal results to show the improvement that is achieved by properly exploiting the correlation between targets View full abstract»

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  • A new look at nonseparable synthetic aperture radar processing

    Publication Year: 1988 , Page(s): 218 - 223
    Cited by:  Papers (12)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (508 KB)  

    The author examines the nonseparable, template correlation approach to digital-strip-mode synthetic-aperture radar (SAR) phase history processing and concludes that it can now outperform the traditional separable approaches in the areas of speed, image quality, control simplicity, and flexibility. A working nonseparable frequency-domain SAR processor is described and evaluated. The image quality is seen to be superior to that resulting from the separable approaches. Based on the working intermediate hardware implementation, the author strongly suggests that future VHSIC and other advanced implementation will provide extremely fast (real time), high-quality, small, flexible SAR processors View full abstract»

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  • Transient processes and stability in an LC chopper

    Publication Year: 1988 , Page(s): 239 - 247
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (612 KB)  

    The analysis of the transient and steady-state processes in LC choppers is presented. The method, used previously for the analysis of processes in grid-connected and self-commutated converters, is adjusted for analysis of LC chopper's processes. The difference equations describing these processes, are obtained and solved. The analytical solution of the problem and the conditions of the transient, steady-state, and stability existence in the chopper are found. Theoretical and experimental results are compared and satisfactory agreement is obtained View full abstract»

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  • Generalized linear solution of proportional navigation

    Publication Year: 1988 , Page(s): 231 - 238
    Cited by:  Papers (18)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (324 KB)  

    Proportional navigation (PN) equations are not solvable in closed form. Linearized solutions have been widely used for PN system analysis and design, but these are based on overly restrictive assumptions regarding the initial geometry, and are valid only for near-tail-chase pursuits. A generalization of the linearized approach is presented which yields more-accurate estimates of pursuer lateral acceleration than the classical linear solutions as verified by comparison with `exact' numerical solutions. Further, the solution is applicable over a much wider range of engagement geometries. The treatment is based on a closed-form quasilinearized solution of the PN equations followed by the small-angle approximation only to line-of-sight (LOS) angle rate View full abstract»

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  • New results on linear prediction for clutter cancellation

    Publication Year: 1988 , Page(s): 275 - 285
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (656 KB)  

    Some moving-target indicator (MTI) techniques are reviewed and those based on the linear prediction theory are examined. A description is given of the effects of the position of the reference sample in an MTI processor on cancelling clutter in a radar system. The analysis of this generalized linear prediction MTI is based on the evaluation of the receiving operating characteristics (ROCs), assuming that the clutter covariance matrix is known a priori as well as the matrix being estimated on line. It is shown by analytical evaluations and Monte Carlo simulations, that the performance is generally insensitive to the position of the reference sample. An additional analysis is carried out to compare the performance of the generalized linear prediction MTI with the MTI based on the Hsiao approach. It is seen that with the formation of the interference of two superimposed clutter sources the generalized linear prediction MTI suffers, in some cases, several decibels of loss View full abstract»

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  • Sequences and arrays with perfect periodic correlation

    Publication Year: 1988 , Page(s): 287 - 294
    Cited by:  Papers (32)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (496 KB)  

    Properties and methods for synthesizing sequences with perfect periodic autocorrelation functions and good energy efficiency are discussed. The construction is extended to two-dimensional perfect arrays. The construction methods used are based mainly on a search in the frequency domain and on a multiplication theorem for periodic sequences and arrays View full abstract»

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  • Comparison of resonant topologies in high-voltage DC applications

    Publication Year: 1988 , Page(s): 263 - 274
    Cited by:  Papers (83)  |  Patents (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (896 KB)  

    Because of their tolerance of transformer nonidealities, resonant converters are considered to be well-suited to high-voltage applications. The series and parallel resonant topologies, as well as a newly discovered hybrid resonant topology are compared for high-voltage applications. Design criteria which incorporate transformer nonidealities are developed and used in the construction of high voltage prototypes for each topology. It is found that the parallel topology leads to the lowest peak switch current and the most ideal behavior View full abstract»

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Aims & Scope

IEEE Transactions on Aerospace and Electronic Systems focuses on the equipment, procedures, and techniques applicable to the organization, installation, and operation of functional systems designed to meet the high performance requirements of earth and space systems.

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Meet Our Editors

Editor-in-Chief
Lance Kaplan
Army Research Laboratory