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Aerospace and Electronic Systems, IEEE Transactions on

Issue 1 • Date January 2007

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Displaying Results 1 - 25 of 38
  • Table of Contents - Jan. 2007, Vol 43 No 1

    Publication Year: 2007 , Page(s): c1
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    Freely Available from IEEE
  • The IEEE Aerospace and Electronic Systems Society - List Staff

    Publication Year: 2007 , Page(s): c2
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  • From the Editor-in-Chief [Appointed Alan R. Jacobsen of the Boeing Company as Technical Editor for Human-Machine Interface for these Transactions]

    Publication Year: 2007 , Page(s): 1
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  • Novel minimum time trajectory planning in terrain following flights

    Publication Year: 2007 , Page(s): 2 - 12
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2043 KB) |  | HTML iconHTML  

    A new methodology has been proposed to enhance inverse dynamics applications in the process of trajectory planning and optimization in terrain following flights (TFFs). The new approach uses a least square scheme to solve a general two-dimensional (2-D) TFF in a vertical plane. In the mathematical process, Chebyshev polynomials are used to model the geographical data of the terrain in a given route in a manner suitable for the aircraft at hand. The aircraft then follows the modeled terrain with sufficient clearance. In this approach the terrain following (TF) problem is effectively converted to an optimal tracking problem. Results show that this method provides a flexible approach to solve the TFF problem especially in conditions where the existing terrain to be flown over is not mathematically well behaved View full abstract»

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  • Almost instant time inference for hybrid partially dynamic Bayesian networks

    Publication Year: 2007 , Page(s): 13 - 22
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2019 KB) |  | HTML iconHTML  

    A Bayesian network (BN) is a compact representation for probabilistic models and inference. They have been used successfully for many military and civilian applications. It is well known that, in general, the inference algorithms to compute the exact a posterior probability of a target node given observed evidence are either computationally infeasible for dense networks or impossible for general hybrid networks. In those cases, one either computes the approximate results using stochastic simulation methods or approximates the model using discretization or a Gaussian mixture model before applying an exact inference algorithm. This paper combines the concept of simulation and model approximation to propose an efficient algorithm for those cases. The main contribution here is a unified treatment of arbitrary (nonlinear non-Gaussian) hybrid (discrete and continuous) BN inference having both computation and accuracy scalability. The key idea is to precompile the high-dimensional hybrid distribution using a hypercube representation and apply it for both static and dynamic BN inference. Since the inference process essentially becomes a combination of table look-up and some simple operations, the method is shown to be extremely efficient. It can also he scaled to achieve any desirable accuracy given sufficient preprocessing time and memory for the cases where exact inference is not possible View full abstract»

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  • Tracking of multiple maneuvering targets using multiscan JPDA and IMM filtering

    Publication Year: 2007 , Page(s): 23 - 35
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1715 KB) |  | HTML iconHTML  

    The paper considers the problem of tracking multiple maneuvering targets in the presence of clutter using switching multiple target motion models. A novel suboptimal filtering algorithm is developed by applying the basic interacting multiple model (IMM) approach and the joint probabilistic data association (JPDA) technique. Unlike the standard single-scan JPDA approach, the authors exploit a multiscan joint probabilistic data association (mscan-JPDA) approach to solve the data association problem. The algorithm is illustrated via a simulation example involving tracking of four maneuvering targets and a multiscan data window of length two View full abstract»

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  • Scan-based emitter passive localization

    Publication Year: 2007 , Page(s): 36 - 54
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (4810 KB) |  | HTML iconHTML  

    This paper investigates the problem of estimating the position of a scanning emitter using a passive scan-based geolocation technique. This is achieved by taking advantage of the geometric constraints introduced by the uniform rotating motion of the antenna main beam as it sweeps across a number of separate receivers. A detailed analysis of the estimation process and accuracy of the emitter position is given and a number of computer simulations showing the benefits of this geolocation technique are also included View full abstract»

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  • Exact Bayesian and particle filtering of stochastic hybrid systems

    Publication Year: 2007 , Page(s): 55 - 70
    Cited by:  Papers (26)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (3774 KB) |  | HTML iconHTML  

    The standard way of applying particle filtering to stochastic hybrid systems is to make use of hybrid particles, where each particle consists of two components, one assuming Euclidean values, and the other assuming discrete mode values. This paper develops a novel particle filter (PF) for a discrete-time stochastic hybrid system. The novelty lies in the use of the exact Bayesian equations for the conditional mode probabilities given the observations. Therefore particles are needed for the Euclidean valued state component only. The novel particle filter is referred to as the interacting multiple model (IMM) particle filter (IMMPF) because it incorporates a filter step which is of the same form as the interaction step of the IMM algorithm. Through Monte Carlo simulations, it is shown that the IMMPF has significant advantage over the standard PF, in particular for situations where conditional switching rate or conditional mode probabilities have small values View full abstract»

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  • Stochastic optimal control guidance law with bounded acceleration

    Publication Year: 2007 , Page(s): 71 - 78
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1060 KB) |  | HTML iconHTML  

    A novel stochastic optimal control guidance law is presented for a missile with bounded acceleration. The nonlinear optimal guidance law (NOGL) is obtained by numerically solving the stochastic optimization problem. Since the certainty equivalence principle is not valid in the investigated problem, the resulting NOGL depends on the conditional probability density function of the estimated states. It is shown that the NOGL is also nonlinear in the estimated zero effort miss distance, and that the probability density function of the miss distance is non-Gaussian. The dependence of the new guidance law on the acceleration limit is investigated and it is shown that only for an extremely large acceleration limit does the proposed guidance law degenerate to the classical optimal linear one View full abstract»

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  • Martian jumping rover equipped with electroactive polymer actuators: A preliminary study

    Publication Year: 2007 , Page(s): 79 - 92
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2208 KB) |  | HTML iconHTML  

    This paper presents results of a preliminary study of feasibility for the application of electroactive polymer (EAP) based actuators to a robotic locomotion system, intended by the European Space Agency (ESA) to operate on the surface of Mars. The system is conceived as an elastic spherical rover, exploiting wind propulsion for surface motion, while adopting an active mechanism for vertical jumping over obstacles. The use of polymeric electromechanical devices is envisaged in order to provide actuation to such a jumping mechanism. Among the available EAP technologies, new contractile linear actuators based on dielectric elastomers arc proposed in this study as suitable devices and two potential solutions concerning their use are designed, modeled, and evaluated via numerical simulations. The best solution reveals interesting simulated performances, enabling jumping of obstacle heights corresponding to more than 7% of the diameter of the rover View full abstract»

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  • Integrated track maintenance for the PMHT via the hysteresis model

    Publication Year: 2007 , Page(s): 93 - 111
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1799 KB) |  | HTML iconHTML  

    Unlike other tracking algorithms the probabilistic multi-hypothesis tracker (PMHT) assumes that the true source of each measurement is an independent realisation of a random process. Given knowledge of the prior probability of this assignment variable, data association is performed independently for each measurement. When the assignment prior is unknown, it can be estimated provided that it is either time independent, or fixed over the batch. This paper presents a new extension of the PMHT, which incorporates a randomly evolving Bayesian hyperparameter for the assignment process. This extension is referred to as the PMHT with hysteresis. The state of the hyperparameter reflects each model's contribution to the mixture, and thus can be used to quantify the significance of mixture components. The paper demonstrates how this can be used as a method for automated track maintenance in clutter. The performance benefit gained over the standard PMHT is demonstrated using simulations and real sensor data View full abstract»

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  • Adaptive boosting for SAR automatic target recognition

    Publication Year: 2007 , Page(s): 112 - 125
    Cited by:  Papers (18)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1367 KB) |  | HTML iconHTML  

    The paper proposed a novel automatic target recognition (ATR) system for classification of three types of ground vehicles in the moving and stationary target acquisition and recognition (MSTAR) public release database. First MSTAR image chips are represented as fine and raw feature vectors, where raw features compensate for the target pose estimation error that corrupts fine image features. Then, the chips are classified by using the adaptive boosting (AdaBoost) algorithm with the radial basis function (RBF) network as the base learner. Since the RBF network is a binary classifier, the multiclass problem was decomposed into a set of binary ones through the error-correcting output codes (ECOC) method, specifying a dictionary of code words for the set of three possible classes. AdaBoost combines the classification results of the RBF network for each binary problem into a code word, which is then "decoded" as one of the code words (i.e., ground-vehicle classes) in the specified dictionary. Along with classification, within the AdaBoost framework, we also conduct efficient fusion of the fine and raw image-feature vectors. The results of large-scale experiments demonstrate that our ATR scheme outperforms the state-of-the-art systems reported in the literature View full abstract»

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  • Effectiveness of the Nash strategies in competitive multi-team target assignment problems

    Publication Year: 2007 , Page(s): 126 - 134
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (631 KB) |  | HTML iconHTML  

    The Nash strategy in game theory has often been criticized as being ineffective in competitive multi-team target assignment problems, especially when compared with other simplistic strategies such as the random or greedy targeting strategies. This criticism arises from the fact that the Nash strategies may yield unpredictable results when paired with non-Nash strategies in non-zero sum games. In addition, the Nash equilibrium is generally more difficult to compute than strategies which do not attempt to anticipate the strategy of the other side. The authors seek to show that in multi-team target assignment problems the Nash strategy is superior to such simplistic strategies while also remaining computationally feasible. To demonstrate this point, an attrition model was considered, consisting of two teams of nonhomogeneous fighting units simultaneously targeting each other and compare the outcomes when various combinations of four targeting strategies are used on each side. The four strategies are: 1) the random strategy where each unit selects its target randomly, 2) the unit greedy strategy where each unit chooses the target that optimizes its own performance only, 3) the team optimal strategy where the units coordinate their choice of targets so as to optimize the overall team performance while ignoring the possible strategy choices by the other team, and 4) the team Nash strategy, calculated under the assumption that the other team is also using a Nash strategy. Because the computational requirements for calculating the team Nash strategies may become unfeasibly large, an efficient method was discussed for approximating the Nash strategies using a neighborhood search algorithm called unit level team resource allocation (ULTRA). The results were compared for all 16 possible combinations of these four targeting strategies and show that for each team the Nash strategy outperforms all other strategies irrespective of the strategy employed by the other team View full abstract»

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  • Performance of multiple-model filters and parameter-sensitivity analysis for likelihood evaluation with shock variance models

    Publication Year: 2007 , Page(s): 135 - 149
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (3141 KB) |  | HTML iconHTML  

    The performance of multiple-model filtering algorithms is examined for shock-variance models, which are a form of linear Gaussian switching models. The primary aim is to determine whether existing multiple-model filters are suitable for evaluating measurement likelihoods in classification applications, and under what conditions such classification models are viable. Simulation experiments are used to empirically examine the likelihood-evaluation performance of suboptimal merging and pruning algorithms as the number of state hypotheses per time step (i.e., algorithm order) increases. The second-order generalized pseudo-Bayes or (GPB(2)) algorithm is found to provide excellent performance relative to higher order GPB algorithms through order five. Likelihoods from fixed-size pruning (FSP) algorithms with increasing numbers of state hypotheses are used to validate the GPB likelihoods, and convergence of the FSP likelihoods to the GPB values is observed. These results suggest that GPB(2) is a reasonable approximation to the unrealizable optimal algorithm for classification. In all cases except very-low-noise situations, the interacting multiple model (IMM) algorithm is found to provide an adequate approximation to GPB(2). Sensitivity of likelihood estimates to certain model parameters is also investigated via a mismatch analysis. As a classification tool, the discrimination capabilities of the measurement likelihoods are tested using an idealized forced-choice experiment, both with ideal and with mismatched models View full abstract»

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  • ASPeCT: Unambiguous sine-BOC(n,n) acquisition/tracking technique for navigation applications

    Publication Year: 2007 , Page(s): 150 - 162
    Cited by:  Papers (26)  |  Patents (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (3153 KB) |  | HTML iconHTML  

    This article presents a new tracking technique for sine-BOC(n,n) (or Manchester encoded) ranging signals, which is most likely to be a part of the new European Global Navigation Satellite System (GNSS), Galileo, signal plan. When traditional sine-BOC(n,n) tracking is considered, although offering excellent performance compared with current signals, it has the main drawback of potentially giving biased measurements. The new method presented herein allows the removal of this threat while maintaining the same level of performance. An adapted version of this technique can also be used for acquisition purposes View full abstract»

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  • Doppler aliasing reduction in SAR imagery using stepped-frequency waveforms

    Publication Year: 2007 , Page(s): 163 - 175
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1534 KB) |  | HTML iconHTML  

    A new technique for eliminating Doppler aliasing artifacts in synthetic aperture radar (SAR) imagery is presented. The technique uses continuous transmission of stepped-frequency (SF) waveforms to generate a simple, but effective, approximation of a two-dimensional |sinc|2 ambiguity function. This approach ensures aliasing artifacts are placed at nulls in a Doppler filter, effectively removing them from the imagery. Various methods of generating SF waveforms are introduced and their performance is quantified. Finally, simulated SAR imagery shows elimination of more than 99% of the aliased energy View full abstract»

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  • System aspects and transmission impairments of active phased arrays for satellite communications

    Publication Year: 2007 , Page(s): 176 - 186
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (4088 KB) |  | HTML iconHTML  

    The communications link and system aspects of active phased arrays that are used in multiple-beam satellite systems are assessed through measurements and analysis. Three link parameters are investigated and their effects on the overall carrier-to-interference ratio (CIR) are quantified. The first parameter is the intermodulation components that are generated at the nonlinear amplifier outputs and contribute to well-formed interference in the far-field radiation of the array. The second is the bit-error ratio (BER) degradation due to the multi-carrier operation of the active array. Measurement results are shown to demonstrate this effect. The third link parameter is the cochannel interference caused by frequency reuse in multiple-beam systems. The paper starts by reviewing early developments of phased arrays for multiple-beam satellite communications applications. A key component in these developments is the modular monolithic microwave integrated circuit (MMIC) beam-forming matrices that generate a number of simultaneous and independently digitally controlled beams View full abstract»

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  • Oscillation suppression for traffic class dependent routing in ISL network

    Publication Year: 2007 , Page(s): 187 - 196
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2013 KB) |  | HTML iconHTML  

    Adaptive per-hop routing in the intersatellite link (ISL) network of a packet-switched, nongeostationary satellite system is addressed. In particular, a traffic class dependent (TCD) routing is proposed with different optimization criteria for different traffic classes. Furthermore, for delay sensitive traffic, performance is enhanced by an exponential smoothing link-cost function, which reduces traffic load oscillations in the network. The performance of the proposed procedures is evaluated in two different traffic scenarios using an appropriate simulation model View full abstract»

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  • Performance analysis of satellite payload architectures for mobile services

    Publication Year: 2007 , Page(s): 197 - 213
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (4389 KB) |  | HTML iconHTML  

    This paper is concerned with the effects on the network performance of moving parts of what is considered traditionally to belong to the ground segment to on board the satellite. Initially, an overview of geostationary satellite communication systems and payload technology is presented, followed by a description of the network architecture and protocols that are the basis of the simulation models. The results obtained from this testbed are presented before concluding with a discussion of the results obtained View full abstract»

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  • Intelligent UUVs: Some issues on ROV dynamic positioning

    Publication Year: 2007 , Page(s): 214 - 226
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2704 KB) |  | HTML iconHTML  

    Intelligent unmanned underwater vehicles (UUVs) fall under two main group categories: the remotely operated vehicles (ROVs), which are characterized by remote operation and presence of a tether cable; and the autonomous underwater vehicles (AUVs), which are characterized by their autonomous behavior and absence of a tether cable. One fundamental issue of the UUV design is the dynamic position control system. This system plays a crucial role together with the sensor architecture in the degree of system autonomy that can be achieved. This paper is concerned with a few issues when dynamically positioning remotely operated underwater vehicles (ROVs). By restricting the operating regime of ROVs to slow velocity requirements the paper investigates the implementation of a few decentralized control strategies and compare their performance measures, which are assessed by simulating a nonlinear ROV system model for each control strategy. Issues concerning input tracking, disturbance rejection, and plant variations are discussed. The evaluations consider the use of linear PID feedback and feedforward variants, and a robust nonlinear control strategies applied to a full order, fully coupled, and nonlinear vehicle model. These evaluations consider a vehicle undertaking standard mission activities where the tether cable dynamics, with load estimates obtained from a lumped mass cable model, and the vehicle actuator system are present. The paper shows that much of the performance deterioration may be attributed mainly due to cable inertia. The authors also verify that the nonlinear robust control strategy does not necessarily allow for better performance over the linear feedback control strategies implemented when vehicle motions are confined to slow velocity profiles. These and other partial results will aid the design of the control system for an underwater vehicle currently under construction View full abstract»

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  • GPS C/N0 estimation in the presence of interference and limited quantization levels

    Publication Year: 2007 , Page(s): 227 - 238
    Cited by:  Papers (10)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2615 KB) |  | HTML iconHTML  

    The carrier-to-noise density ratio (C/N0) is considered an important parameter describing the GPS receiver performance. This paper compares the performance of two popular coarse-acquisition (C/A) C/N0 algorithms appearing in literature: the variance summing method (VSM) (Psiaki et al., 2003, Psiaki, 2001), and the power ratio method (PRM) (Van Dierendonck, 1996, Sayre, 2003), in terms of their estimates in 1) additive white Gaussian noise (AWGN), 2) narrowband continuous wave interference (CWI), 3) their response to quantization and saturation effects, and their 4) dynamic range. The algorithms were implemented as a part of a software receiver. Two LI GPS data sets are examined; one was obtained from a GPS raw data collection setup, while the other was obtained from a GPS signal simulator. The collected set was stored with almost constant C/N0 level while the simulated one contained variable C/N0 levels. The effect of adding AWGN on the C/N0 estimate was directly proportional with the noise power. The C/N0 estimates suffered more when the CWI frequency was closer to the IF of the receiver. The PRM suffered from saturation at higher C/N0 levels. The VSM showed good tracking at high C/N0 levels and better immunity to limited quantization levels, while its C/N0 estimate suffered from rapid fluctuations in power levels when sudden power steps occurred View full abstract»

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  • Sequential nonlinear tracking using UKF and raw range-rate measurements

    Publication Year: 2007 , Page(s): 239 - 250
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (3156 KB) |  | HTML iconHTML  

    The three-dimensional (3D) converted measurements filtering (CMF) with both converted position and raw range-rate measurement is proposed to solve the Doppler radar target tracking, where the error between radar-target range and range rate are correlated. Firstly, not using pseudomeasurement constructed by product of range and range rate to reduce the high nonlinearity, the raw range-rate measurements are utilized by unscented Kalman filter (UKF), where the converted errors of the position and the range rate are decorrelated, then linear part (position measurements) and nonlinear part (range-rate measurement) are sequentially processed by Kalman filter (KF) and UKF. Secondly, based on the assumption of small measurement error, the mean and covariance of converted measurement errors are derived by second-order Taylor series expansion. Finally, the influence of the correlated coefficient rho between the range and range rate, and the range-rate noise deviation sigmar are taken into account and extreme values of rho and sigmar are used in Monte Carlo simulations. The results show that the proposed method is, in a sense, effective and practical View full abstract»

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  • Phased array of large reflectors for deep-space communication

    Publication Year: 2007 , Page(s): 251 - 261
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2013 KB) |  | HTML iconHTML  

    In this paper the problem of uplink array calibration for deep-space communication is considered. A phased array of many modest-size reflectors antennas is used to drastically improve the uplink effective isotropic radiated power of a ground station. A radar calibration procedure for the array phase distribution is presented using a number of in-orbit targets. Design of optimal orbit and the number of calibration targets is investigated for providing frequent calibration opportunities needed for compensating array elements phase center movements as the array tracks a spacecraft. Array far-field focusing based on the near-filed in-orbit (low Earth orbit (LEO)) calibration targets is also presented and array gain degradation analysis based on the position error of the array elements and in-orbit targets has been carried out. It is shown that errors in the in-orbit targets positions significantly degrade the far-field array gain while the errors in array elements positions are not very important. Analysis of phase errors caused by thermal noise, system instability, and atmospheric effects show insignificant array gain degradation by these factors View full abstract»

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  • Aeronautical telemetry using multiple-antenna transmitters

    Publication Year: 2007 , Page(s): 262 - 272
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1848 KB) |  | HTML iconHTML  

    The placement of multiple antennas on an air vehicle is one possible practice for overcoming signal obstruction created by vehicle maneuvering during air-to-ground transmission. Unfortunately, for vehicle attitudes where more than one of these antennas has a clear path to the receiving station, this practice also leads to self-interference nulls, resulting in dramatic degradation in the average signal integrity. This paper discusses application of unitary space-time codes such as the Alamouti transmit diversity scheme and unitary differential space-time codes to overcome the self-interference effect observed in such systems. The mathematical foundations of these techniques within the context of this application as well as computational performance gains associated with their implementation are provided. Issues such as the cost of channel estimation for trained techniques as well as the throughput performance of nondifferential and differential schemes for realistic air-vehicle motion are analyzed View full abstract»

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  • Importance sampling for characterizing STAP detectors

    Publication Year: 2007 , Page(s): 273 - 285
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1404 KB) |  | HTML iconHTML  

    This paper describes the development of adaptive importance sampling (IS) techniques for estimating false alarm probabilities of detectors that use space-time adaptive processing (STAP) algorithms. Fast simulation using IS methods has been notably successful in the study of conventional constant false alarm rate (CFAR) radar detectors, and in several other applications. The principal objectives here are to examine the viability of using these methods for STAP detectors, develop them into powerful analysis and design algorithms and, in the long term, use them for synthesizing novel detection structures. The adaptive matched filter (AMF) detector has been analyzed successfully using fast simulation. Of two biasing methods considered, one is implemented and shown to yield good results. The important problem of detector threshold determination is also addressed, with matching outcome. As an illustration of the power of these methods, two variants of the square-law AMF detector that are thought to be robust under heterogeneous clutter conditions have also been successfully investigated. These are the envelope-law and geometric-mean STAP detectors. Their CFAR property is established and performance evaluated. It turns out the variants have detection performances better than those of the AMF detector for training data contaminated by interferers. In summary, the work reported here paves the way for development of advanced estimation techniques that can facilitate design of powerful and robust detection algorithms 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