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A new efficient method to obtain high resolution ISAR images in the case of missing observation data is presented. The available data segments are modeled by 2-D linear prediction of 2-D Cartesian frequency spectra using 2-D orthogonal lattice filters. Then the prediction models are used to estimate the missing data segments. It is shown that the IFT processing of the resulting data achieves better...
Through-the-wall radar imaging attempts to image complex scenes within enclosed structures. While most of the high-resolution imaging techniques assume point targets, indoor imaging requires dealing with single or multiple walls which are extended targets in nature and violate the point-target assumption. In order to provide high quality imaging, we need to consider point targets and extended targets...
This paper proposes a new parameter based method of SAR image feature extraction and complex image information retrieval. The methodpsilas groundwork is the Fast Fourier Transform, each of the proposed parameters being built on a Fourier Transform basis. We suggest that by the use of several image bands formed of distinct spectral signatures of the original complex image, one can obtain a valid spectral...
The main idea that motivates this study is to improve the resolution of a radar mounted on an airplane, looking in the forward direction: this can be obtained by forming a synthetic array along the airplane line of flight. We term this new concept as ldquoForward-Looking Synthetic Aperture Radarrdquo (FLoSAR). We present a feasibility study that analyses the system geometry, evaluates the achievable...
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...
In radar imaging, it's well known that relative motion or deformation of parts of illuminated objects induce additional features in the Doppler frequency spectra. These features are called micro-Doppler effect and appear as sidebands around the central Doppler frequency. They can provide valuable information about the structure of the moving parts and may be used for identification purposes. Previous...
Defence Research and Development Canada - Ottawa has developed an experimental airborne radar referred to as the X-band Wideband Experimental Airborne Radar (XWEAR). The radar was designed to support research into SAR imaging of fixed and moving targets (ocean and land), time-frequency analysis of moving targets, clutter suppression for GMTI radar, and ocean surveillance for small and large target...
It is efficient to enlarge the radar bandwidth based on multi-band fusion. However, the former research on multi-band fusion did not take velocity into consideration. When the velocity is very high or pulse width is long, ignoring the impact of high speed the range resolution will deteriorate heavily. In this paper the authors develop a new method of forming high resolution range profile of fast moving...
Automatic target recognition (ATR) performance evaluation has become an important subject in ATR theory community since the last two decades. The extended operation condition (EOC) and system cost are two key aspects in ATR performance evaluation. For the situation of air-to-ground (A-G) ATR using high range resolution (HRR) data, this paper analyzes the influence of target type number on ATR system...
Scope of the paper is to describe a technique to improve the multifunctional radar capabilitiesof tracking and classification of non-cooperative targets. The result is achieved by joining together the following two functions: (i) a tracker architecture based on Interacting Multiple Model approach and (ii) the processing of large bandwidth (either synthetic or instantaneous) signals to form Medium...
The rotational state of a planet or satellite bears crucial physical information on the bodypsilas dynamical evolution and deep internal structure. For planets or satellites in a Cassini state the obliquity (the angle between the rotational and orbital angular momentum) and physical librations, combined with the measurement of the second degree coefficients of the gravity field, could provide the...
In the 90s, Galileo Avionica (GA Radar Systems Business Unit) has developed the GRIFO Radar, a multimode-multirole pulse Doppler radar, devoted to occupy an important role in the family of the radar for weapon release. In the last 15 years more than 400 units have been sold to five Air Forces, for more than 100,000 hours of operative flights. The need for the implementation of high-resolution modes,...
COSMO-SkyMed is the Italian Remote Sensing programme which foresees the utilization of a constellation of four SAR Satellites in Low Earth Orbit, dedicated to the management, control and exploitation of Earth resources for civil and defence applications. The program is completely funded by the Italian Government, mainly through the Italian Ministry of Research (MIUR) and the Ministry of Defence (I-AD)...
Cross-range resolution in spotlight synthetic aperture radar (SAR) is primarily a function of the angular extent (Deltathetas) over which data is collected. In [1], the authors proposed a method for improving cross-range resolution for a given Deltathetas by use of frequency diverse array (FDA) techniques. The goal was to exploit an apparent increase in Deltathetas to improve cross-range resolution...
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...
This paper considers the problem of high-resolution imaging of the environment formalized in terms of a nonlinear ill-posed inverse problem of nonparametric estimation of the power spatial spectrum pattern (SSP) of the wavefield scattered from an extended remotely sensed scene (referred to as the scene image) via processing the discrete measurements of a finite number of independent realizations of...
The introduction of a novel scanning technique, named terrain observation by progressive scan (TOPS) allows the improvement of the DTAR in multi swath radar images. The trade off between resolution in range and revisit time (the number of swaths) is very efficient. Some results of the modeling and simulation of this technique are discussed, as well as an application to ship traffic monitoring, revisiting...
A single algorithm for various radar imaging applications is presented. The idea behind the proposed approach is that any motion between a radar and an imaged target can be modelled as the composition of pure translational and rotational components. Novel techniques for estimating and compensating these two motion components are discussed and their application to real radar data for different classes...
Orbital planning and formation flying control of SABRINA mission will allow different observation geometries characterized by inter satellites distances (baseline) variable from hundreds meters to some hundreds of kilometers. In a so vast scenario, a wide range of bistatic techniques are applicable and testable, ranging from cross and along track interferometry to multi-channel techniques and large...
In this study, the support vector machine (SVM) was used as a classifier to identify aerospace objects. Radar target identification based on high resolution range profiles (HRRPs) received much attention because of its reduced complexity than those using two-dimensional (2-D) ISAR images. Therefore range profiles were used as feature vectors to represent radar data. Data sets which are for training...
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