The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This talk will provide an overview of adaptive radar signal processing starting from the early work of Howells, Applebaum and Widrow on adaptive arrays. The sample matrix inverter (SMI) method and its variants will be discussed in some detail. The focus of the discussion will be on the constant false alarm rate (CFAR) characteristics. These methods are based on the formation and inversion of a sample...
The paper presents recent progress of the state of the art of space-borne radar technology in case of either earth-orbiting or planetary-orbiting satellites and space probes, respectively. In addition to that recent progress is also discussed concerning specific inversion techniques to evaluate radar measurements, i.e. the art of deriving the relevant physical quantities to be determined such as terrain...
Traditional STAP detectors require a secondary training data set that is target free and homogeneous with the cell under test (CUT). Hybrid detectors have been proposed for heterogeneous environments where the secondary data suffers from a statistical mismatch with respect to the interference in the CUT. These algorithms employ the generalised inner product (GIP) as a heterogeneity measure and eliminate...
In this paper, we propose and assess an adaptive radar detector that can adjust its ldquodirectivityrdquo through a real scalar parameter. Proper choices of such a parameter return, as special cases, the well-known Kellypsilas GLRT and the recently introduced W-ABORT detector. More important, through the tuning of the above parameter one can control the level to which sidelobe signals are rejected...
Derived from statistical conditional optimization criteria, the auxiliary-vector (AV) detection algorithm starts from the target vector and adding non-orthogonal auxiliary vector components generates an infinite sequence of tests that converges to the ideal matched filter (MF) processor for any positive definite input autocorrelation matrix. When the input autocorrelation matrix is replaced by a conventional...
Calculating accurate low-rank covariance estimates for sensor arrays with a large number of elements is a common task in signal processing. Many algorithms make use of the exact spectral decomposition of the empirical covariance structure-but the singular value decomposition is often too costly in practice, owing to array size or constraints on computation. Recent approaches geared toward the approximate...
Post-Doppler methods are rank reduction techniques to reduce temporal dimensions by applying the Doppler filter and can reduce the processing time than full degrees-of-freedom (DOF) space-time adaptive processing (STAP). In post-Doppler methods, multi-bin post-Doppler methods are generally used to improve the performance of signal-to-interference-plus-noise ratio (SINR). However, it is necessary to...
The utilization of diversity in radar systems has shown improvements over conventional beamforming phased array radars in many aspects of the system performance including target detection probability, the number of identifiable targets, and beam-pattern synthesis. When linearly independent signals are transmitted, the signals received from targets at different locations are also linearly independent...
We analyze the performance of a recently described class of two-dimensional autoregressive parametric models for space-time adaptive processing (STAP) in airborne radars on the DARPA side-looking radar model known as KASSPER Dataset 1. We investigate the trade-offs between signal-to-interference-plus-noise ratio (SINR) degradation (with respect to the optimal clairvoyant receiver) due to the mismatch...
In this paper, a new spectral estimation method, which is based on the rank-deficient sample covariance matrix, is proposed. The new method applies the amplitude and phase estimation (APES) filter and the Capon weight simultaneously on the data matrix to obtain the complex amplitude estimate of the spectral line of interest. Because the sample covariance matrix is singular, a rank-deficient version...
This paper deals with covariance matrix estimation for radar detection in non-Gaussian noise modeled by spherically invariant random vector (SIRV). In many applications, it is possible to assume a particular structure for the clutter covariance matrix: this is the case for instance for active systems using a symmetrically spaced linear array or pulse train. In this paper, we propose to use the particular...
This paper presents the model and analysis of a frequency-diverse radar system. Multistatic radar systems provide an inherent spatial diversity by processing signals from different platforms which view a potential target from different aspect angles. By using different frequencies at each platform, an additional diversity gain can be obtained on top of the advantages of spatial diversity. Here, since...
In this paper a doubly adaptive scheme is presented for detection and jammer cancellation by airborne monopulse radar, equipped with three receiving channels. An adaptive auxiliary selection technique is proposed to decide which is the most effective couple of auxiliary antennas in each condition, assuming a slowly changing jamming environment. This leads to a doubly adaptive jammer cancellation scheme:...
In this paper, we consider the problem of knowledge-aided covariance matrix estimation and its application to adaptive radar detection. We assume that an a-priori (knowledge-based) estimate of the disturbance covariance M, derived from a physical scattering model of the terrain and/or of the environment, is available. Hence, starting from a set of secondary data, we evaluate the maximum likelihood...
Conformal arrays possess certain desirable characteristics for deployment on unmanned aerial vehicles and other payload-limited platforms: aerodynamic design, minimal payload weight, increased field of view, and ease of integration with diverse sensor functions. However, the conformal arraypsilas nonplanar geometry causes high adaptive losses in conventional space-time adaptive processing (STAP) algorithms...
In this paper a technique to conduct tomographic analyses of forested areas through multiple, coherent SAR images is presented. This technique differs from other methods existing in literature in that it may be regarded as a natural extension of SAR interferometry to the case where several distributed targets are present within the system resolution cell. In this way, it is possible to estimate the...
New operational requirements for stealth targets detection in dense & inhomogeneous clutter are emerging (littoral warfare, low altitude asymmetric threats, battlefield in urban area...). Classical radar approaches for Doppler & array signal processing have reached their limits. We propose new improvements based on advanced mathematical studies on geometry of SPD matrix (symmetric positive...
In this paper the STAP detector based on the low-rank approximation of the normalized adaptive matched filter (LRNAMF) is investigated for its false alarm probability (FAP) performance. An exact formula for the FAP of the LRNAMF detector is derived using the g-method estimator [4]. The non-CFAR behavior of this detector is shown via simulations using different models for the clutter-plus-noise covariance...
Digital audio/video broadcasting (DAB/DVB-T) is already available in a large area of Europe. The advantage of using these signals for passive air surveillance is the disposability of a large range of illuminators sending an easily decodeable digital broadcast signal. In the considered multi-static scenario, one observer provides bistatic time difference of arrival (TDoA) and Doppler measurements....
The parametric Rao and GLRT detectors, recently developed by exploiting a multichannel autoregressive (AR) model for the spatially and temporally colored disturbance, were shown to perform well with limited or even no range training data for the airborne radar configuration. In previous computer simulation studies of these parametric detectors, the disturbance was generated as a multichannel AR process...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.