This paper presents a novel synthetic aperture method, which can be used to reduce the average sidelobe level of a random spherical volumetric array. The technique exploits a general property of random arrays in which...
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ISBN:
(纸本)1424403081
This paper presents a novel synthetic aperture method, which can be used to reduce the average sidelobe level of a random spherical volumetric array. The technique exploits a general property of random arrays in which the average sidelobe level is inversely proportional to the number of elements present.
For a set of T independent N-variate Gaussian training samples (T < N), we derive a test for discriminating between stationary autoregressive models of order m, AR(m), and time-varying autoregressive models of orde...
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ISBN:
(纸本)1424403081
For a set of T independent N-variate Gaussian training samples (T < N), we derive a test for discriminating between stationary autoregressive models of order m, AR(m), and time-varying autoregressive models of order m, TVAR(m).
Multifunction phased array systems with radar, telecom, and imaging applications have already been established for flat plate phased arrays of dipoles, or waveguides. In this paper the design trades and candidate opti...
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ISBN:
(纸本)1424403081
Multifunction phased array systems with radar, telecom, and imaging applications have already been established for flat plate phased arrays of dipoles, or waveguides. In this paper the design trades and candidate options for combining the radar and telecom functions of the deep space network (DSN) into a single large transmit array of small parabolic reflectors will be discussed. In particular the effect of combing the radar and telecom functions on the sizes of individual antenna apertures and the corresponding spacing between the antenna elements of the array will be analyzed. A heterogeneous architecture for the DSN large transmit array is proposed to meet the radar and telecom requirements while considering the budget, scheduling, and strategic planning constrains.
In this paper, an alternative Target Density Function (TDF) is proposed to image the radar targets in a dense target environment. It is obtained by considering a novel range and scanning angle plane different from the...
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ISBN:
(纸本)1424403081
In this paper, an alternative Target Density Function (TDF) is proposed to image the radar targets in a dense target environment. It is obtained by considering a novel range and scanning angle plane different from the conventional methods. An alternative method is briefly proposed for smoothing the target density function by taking advantage of Walsh functions. Although the imaging is obtained via the phased array radars, the problem associated with beamforming in linear phased array radar system is bypassed in this new algorithm.
We describe a method of tuning a simple detection process of stationary targets in SAR images. The tuning metric accounts for the squared-error performance of prescient estimators of target location and reflectivity. ...
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ISBN:
(纸本)1424403081
We describe a method of tuning a simple detection process of stationary targets in SAR images. The tuning metric accounts for the squared-error performance of prescient estimators of target location and reflectivity. The efficiencies of these prescient estimators are compared to their Cramer Rao bounds (CRBs). The off-line tuning is performed by collecting statistics of scatterer estimation in SAR images created using sparse-array spotlight mode simulations.
Conventional MUSIC (MUltiple signal Classification)rraethod, which is a well-known super-resolution technique that employs amonostatic configuration, degrades severely when themultiple targets are deterministic becaus...
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ISBN:
(纸本)1424403081
Conventional MUSIC (MUltiple signal Classification)rraethod, which is a well-known super-resolution technique that employs amonostatic configuration, degrades severely when themultiple targets are deterministic because the rank of the covariancematrix collapses to the value of one regardless of the number of targets. FRM (Frequency Response Matrix) [2, 7], with its multistatic configuration, is also a super-resolution technique and can complament, MUSIC in the target randomness spectrum. This paper demonstrates that conventional MUSIC performs better for targets with strongly random (complex) amplitudes and FRM performs better for target with weakly random amplitudes (best for deterministic amplitudes).
We propose a method of indoor localization using arraysensors. This method uses not only the signal strengths of received signals, but also the spatial information of impinging signals on arraysensors. The signal su...
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ISBN:
(纸本)1424403081
We propose a method of indoor localization using arraysensors. This method uses not only the signal strengths of received signals, but also the spatial information of impinging signals on arraysensors. The signal subspaces, which include information about the strengths and angles of arrival of impinging signals on the arraysensors, are used to identify the location of the terminal. We use the cosines of the principal angles between the signal subspaces of the spatial covariance matrices of the signals received at an array antenna to measure the similarity between signals transmitted from two locations. We conducted an experiment indoors to confirm the validity and effectiveness of our method. The experimental results confirm its effectiveness.
Source location accuracy can be dramatically degraded by the inaccuracy in the sensor positions. The sensor position errors need to be taken into account in order to improve the source location estimate. This paper pr...
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ISBN:
(纸本)1424403081
Source location accuracy can be dramatically degraded by the inaccuracy in the sensor positions. The sensor position errors need to be taken into account in order to improve the source location estimate. This paper presents an algorithm based on the Taylor-series technique to estimate the location of an emitting source in the presence of random sensor position errors, where the data measurements are angle-of-arrivals (AoAs). The proposed algorithm jointly estimates the source and sensor positions iteratively by using Taylor-series linearization. Simulation results indicate that the proposed method approaches the CRLB accuracy for both near-field and far-field sources.
Computed Spectroscopy (TM) (CS) is a new approach to hyperspectral imaging recently introduced by the authors [1]*. The CS technique uses an adjustable optical array, which can be considered to be a form of delay-and-...
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ISBN:
(纸本)1424403081
Computed Spectroscopy (TM) (CS) is a new approach to hyperspectral imaging recently introduced by the authors [1]*. The CS technique uses an adjustable optical array, which can be considered to be a form of delay-and-sum passive beamformer. Adopting this point of view, such an array can be analyzed using the (difference) coarray [2], and a previous publication by the present authors [1] features a brief coarTay-based analysis. In the present paper we review the Computed Spectroscopy method, give a coarray-based analysis of the approach, show how numerical problems arise in the reconstruction of wavenumber spectra at low spatial frequencies and give a method for addressing these problems in the computation. Additionally, we discuss an improved approach to discretization of the image formation model.
In this paper we propose an algorithm for angle and polarization estimation of non-coherent sources using real-world polarimetric antenna arrays. In order to construct an accurate model of an antenna array, we exploit...
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ISBN:
(纸本)1424403081
In this paper we propose an algorithm for angle and polarization estimation of non-coherent sources using real-world polarimetric antenna arrays. In order to construct an accurate model of an antenna array, we exploit its Effective Aperture Distribution Function (EADF). This model contains information on the array response for a vertical and horizontal excitation, the directional characteristic of each element, and array imperfections. Here, we propose a method stemming from the RARE (RAnk-Reduction Estimator) algorithm. It performs fast (search-free) DoAs and polarization coefficients estimation. Throughout simulation results, we verify that the algorithm has close to optimal statistical performance with polarimetric real-world arrays. We present the statistical performance for three different array configurations.
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