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An adaptive (or cognitive) radar operates by sensing the environment and accordingly adopts an optimal transmit-receive structure. To this end, in the literature, matched illumination (MI) principles have been investigated to realize this concept, algorithms have been developed for the different components in such radars, and the entire framework validated through numerical simulations. However, these...
The article presents the research on hydrographic data integration for the purpose of environment modelling. The approach taken by the authors assumes three basic sources of underwater information: sonar images, bathymetric grid and contour map of magnetic anomaly derived from hydrographic surveys conducted in marine waters. The article discusses the characteristics of each set of data and presents...
This paper presents a method of fusion of identification (attribute) information provided by two types of sensors: combined primary and secondary (IFF) surveillance radars and ESM (Electronic Support Measures). In the first section is adopted the basic taxonomy of attribute identification in accordance with the standards of STANAG 1241 ed. 5 and STANAG 1241 ed. 6 (draft). These standards provide the...
Air-launched GPR (Ground Penetrating Radar) systems have the advantage of longer standoff distances compared to traditional ground-coupled GPR systems. One important drawback of these systems is that the energy coming from targets located on the ground is significantly stronger than from underground targets, in such a way that even the sidelobes of the former are usually higher than the main lobe...
In this paper we consider the problem of tracking a target in a 2D space whose model is based on a constant velocity assumption (up to a process noise) in the Frenet-Serret frame (or intrinsic coordinates). This model is particularly suited to straight lines and coordinated turn motions. Then, we adapt the Invariant Extended Kalman Filter (IEKF), as in [1], a novel variant of the EKF on Lie groups,...
The problem of minimizing dwell time in multifunction phased array radar is considered. Target of interest is assumed to fluctuate according to a generalization of Swerling family and the parameters of fluctuation model are assumed to be known. The a'priori position of the target is uncertain. Optimization, whose variables include pulse count and array transmit beampattern, is carried out subject...
Electronic Phased-Array Radars offer new possibilities for Radar Search Pattern Optimization by using bi-dimensional beam-forming and beam steering, along both elevation and azimuth axes. The Radar Search Pattern Optimization problem can be approximated as a Set Cover problem and solved using Integer Programming methods. This approximation can be extended to account for direction-specific scan update...
Multifunction radars (MFR) have to achieve their capability requirements in an increasingly complex environment, populated with diverse and hostile targets (e.g. low RCS, low speed targets in clutter or high speed, ballistic targets) in saturating scenarios (due to e.g. RF interference or threats). These radar systems are increasingly exploiting active electronically scanned array (AESA) technology...
Radar sensors become typical components for automotive driver assistance systems and autonomous driving. The widespread use of this sensor type leads to an increasing risk of unwanted interferences. Those interferences can severely degrade the detection performance and cause sensor blindness. To overcome this problem, this paper describes a method to estimate and remove interfering signals in data...
Radar sensors play an important role in the technology field of autonomous driving. In contrast to optical cameras, they work reliable by night, mist, snow and fog. Recent radar sensors have problems in near-field scenarios. In this paper, we investigate how the technique of synthetic aperture radar (SAR) can be used to reconstruct the 3D near-field environment up to 30m with several physical radar...
With the introduction of DVB-T2 in Germany and other European countries as new standard for Digital Video Broadcasting the underlying passive radar signal processing has also to be adapted, because the currently used predecessor, DVB-T, is not compatible to DVB-T2 on the physical layer. DVB-T2 has been improved in order to achieve a higher data rate and to allow more flexibility for different use...
The detection performance of a passive radar systems is generally determined by the received reference and surveillance signals purity. In recent times a number of interference cancellation techniques have been researched to deal with the disturbances on the surveillance channel. The variety of different methods operate in the space, time and frequency domains with having different implementations...
Classical ISAR imaging usually is based on the polar re-formatting algorithm making use of the fast Fourier transform. If the observed aspect angle change is large enough, several partial segments can be processed separately, the resulting partial images can be summed incoherently to a multi-look image with reduced noise and speckle level and exhibiting more details, since some parts of the objects...
A multistatic passive coherent location system has been designed during an eight month lasting trial starting in the end of 2015. The demonstration system exploits the regional single-frequency network (SFN) of DVB-T transmissions from two transmit stations in the area of Munich, Germany. It features multiple pre-existing receiving sites of a TDOA-based passive emitter tracking system to localize...
Multiple target tracking in over-the-horizon radar (OTHR) suffers from two major challenges due to the multipath propagation phenomenon. The first is multipath detection that detects appearing and disappearing targets automatically, while one target may produce s tracks for s propagation paths. The second is multipath tracking that calculates the target-to-measurement-to-path assignment matrices to...
A reduced-rank (RR) space-time adaptive processing (STAP) method for simultaneous clutter plus jamming suppression in airborne multiple-input multiple-output (MIMO) radar is proposed. Firstly, the system parameters of MIMO radar STAP are utilized to construct the clutter subspace offline. Next, an auxiliary channel allocated with the matched filter orthogonal to all the transmit waveforms is utilized...
An ionospheric condition monitoring system (ICMS) is a critical component of over-the-horizon radar (OTHR), providing advice on frequency channel selection and availability for operation. Because of dynamically changing atmospheric, ionospheric and magnetic conditions, the over-the-horizon radar (OTHR) transmit carrier frequency needs to be adjusted regularly to maintain constant illumination of targets...
Synthetic Aperture Radar (SAR) spaceborne imaging with High Resolution Wide Swath (HRWS) capabilities has been the subject of increasing interest and active research, driven by applications posing requirements of high spatial resolution and short revisit times which cannot be directly fulfilled with conventional system architectures. In this context, the paper examines a combination of two promising...
Passive radar uses illuminators of opportunity instead of a dedicated radar transmitter. A number of already transmitted signals can be used, however, their nature is mostly continuous and their utilization is a complicated task. One of the key limiting factors of passive radar is the strong direct signal interference (DSI), even though many physical and signal processing countermeasures have already...
The paper presents a concept of the parametric autofocus method for Passive Inverse Synthetic Aperture Radar (ISAR) imaging of air targets. To create a focused ISAR image, the precise knowledge of an object trajectory is required. In this paper a theoretical model of the target motion and an algorithm for finding the best set of estimated motion parameters are described. Simulated results of ISAR...
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