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.
The paper deals with the characteristics of a lightning protection system (LPS) for a fixed and a mobile radars. The LPS design includes external (LPE) and internal (LPI) system as well as protection measures against lightning electromagnetic pulse (LEMP) of internal electrical and electronic systems (i.e. air terminations, down conductors, earthing arrangement, internal equipotential bonding. cable...
The tracking of storm centres in radar data is of particular importance for short term weather prediction and specifically thunderstorm prediction. This paper presents a method to track storm centres in terrestrial radar images. Mean shift segmentation is used to outline storm centres and mean shift tracking to locate the storm in the consecutive images. Results demonstrate the ability of the method...
This talk will try to briefly review what developments have had an impact on radar (that is, what concepts and technology have made radar of value in the past), what radar concepts and technology were important in the past but might not be so important in the future, what things appear to be of current interest in radar but are not as likely to see lasting utility (that is, ideas that one should examine...
The tutorial is an overview of tracking and data fusion for surveillance systems with applications both to defense and civilian systems. It is divided into four parts: Part 1 - Filtering: Covers the topics related to state estimation for stochastic dynamic systems: optimal Bayesian estimator, Kalman filter, nonlinear filters (extended and unscented Kalman filter, Gaussian sum filter, particle filter);...
Cross-correlation based image subtraction for detection of targets within an urban structure from synthetic aperture radar images is presented. In surveillance operations requiring re-imaging of the same scene, small displacements in array element locations may cause large phase and amplitude offsets. Subsequently, clutter will not cancel out, but will rather persist when subtracting two images, one...
In this paper, we present a new segmentation algorithm based on subband decomposition for SAR images. The decomposition of the SAR images into subband images is performed by 2D four channel non separable filter bank having lattice structure. The four channel filter bank with lattice structure has perfect reconstruction property, while it guarantees good stop band attenuation for each of the analysis...
An algorithm based on the exact maximum likelihood (ML) estimator for retrieving the mean stem volume of mature forest stands on relatively flat ground is presented. A VHF-band forest backscatter model at the individual tree level is used to derive the algorithm. The model interprets the tree trunk volume as a random variable and employs a concept of random forest reflection coefficient to characterize...
Weather radar polarimetric techniques have been widely studied due to their potential to improve radar rainfall estimation and to infer on the microphysical characteristics of clouds and precipitation. Nowadays, polarimetric techniques are receiving an increasing attention from meteorological services. In fact, programs aiming at upgrading national weather radar networks with polarimetry are ongoing...
Automatic target recognition (ATR) is an important capability for defense application. ATR removes the human operator from the process of target acquisition and classification, reducing the reaction time to possible threats and can be used to gun target engagement. This paper presents one technique used to solve the automatic target recognition problem in synthetic aperture radars (SAR) images, that...
This paper addresses the effect of wind on target detection performance using a space based radar platform. Forests and lakes are constantly being modulated by wind, which then affects the radar pulse returns by suitably amplitude modulating the temporal returns, thus affecting the Doppler. Billingsley has modeled the windblown autocorrelations using a real symmetric function that is the sum of a...
COSMO-SkyMed is the largest Italian investment in Space Systems for Earth Observation, commissioned and funded by Italian Space Agency (ASI) and Italian Ministry of Defense (MoD). It consists of a constellation of Low Earth Orbit mid-sized satellites, each carrying a multi-mode high resolution Synthetic Aperture Radar (SAR) instrument operating at X-band and a full featured Global Ground Segment to...
In this paper we consider the problem of the estimation of the digital elevation model (DEM) of a ground scene starting from dual baseline interferometric synthetic aperture radar (SAR) signals. classical maximum likelihood (ML) estimation techniques require the knowledge of the joint probability density function (PDF) of the two measured interferometric phases. Usually the joint PDF expression is...
Radio interference suppressing is a main problem to be solved in high frequency (HF) radar system. To effectively cancel the interference, the parameters of the polarization filter should timely adapt to the variation of the polarization of the interference, which may impact the amplitude and phase of the desired signal passing through the same polarization filter during the coherent integration time...
In the present paper an analytical description of three-dimensional (3-D) inverse synthetic aperture radar (ISAR) geometry is performed. A model of 3-D ISAR signal with Barkerpsilas phase code modulation (BPCM) is created. Image reconstruction procedure including range compression by cross correlation over fast time record data and azimuth compression by fast Fourier transform over slow time row data,...
The problem of very high resolution Inverse Synthetic Aperture Radar (ISAR) imaging of moving targets is considered. In particular, the focus of the paper is on the estimation of those parameters concerning the target rotation motion, needed to correctly focus and scale the target images. To this aim, two new estimation techniques are proposed based respectively on the Maximum Likelihood and Constrast...
Passive radars are not at all new to the radar community though they lately raised interest among researchers for some specific features that make them more appealing than classic active radar systems. In fact, having the TX and RX located at two different positions, and the adoption of signals carrying other kinds of information such as GSM (either classical or the 1800/1900 MHz version) or FM modulated...
The objective of this work is to develop optimal polarimetric Constant False Alarm Rate (CFAR) ship detection system. Polarimetric transformation/decompositions, clutter analysis, modeling, Principal Component Analysis (PCA), and multi-CFAR detection are the necessary components of optimal polarimetric CFAR ship detectors. The resulting CFAR detector outperforms the conventional polarimetric CFAR...
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.