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In this paper, we describe a new parameter estimation methodology called transpose domain filtering (TDF). TDF is a processing formulation that that is different from conventional processing (e.g., beamscan processing) in that the weight vector is applied in the domain that lies transpose to the signal model. For a typical radar array processing problem, this means TDF would apply the weight vector...
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...
In a synthetic aperture radar (SAR) image of the ground, moving targets appear at locations different from their true instantaneous locations on the ground. In a corresponding interferometric phase image, all points on the ground nominally appear as a continuum of phase differences while the moving targets appear as discontinuities. By threshold comparisons within the intensity and the phase images,...
A new inversion method to obtain the real state of the ionosphere with an oblique sounder is presented. This method takes some points on the backscatter ionogram obtained by scanning in elevation to estimate the parameters of the electronic density profile of the ionosphere. With these parameters, the real position of the target can be obtained by using a ray tracing.
The concept of multiple-input multiple-output (MIMO) radar is recently proposed inspired by recent advances in MIMO communications. A recently proposed statistical MIMO radar configuration is considered here, in which the transmit array antennas are widely spaced to enable spatial diversity with respect to the targets, while the receiver is an uniform linear array with the elements spaced half a wavelength...
In this paper, a space-time clutter model with non-Gaussian statistics for varying airborne bistatic radar scenarios is presented, which can be widely employed to assess the performance of bistatic space-time adaptive processing (STAP) algorithms in realistic clutter environments of interest. To extract the fundamental properties of bistatic clutter, i.e. the range dependency of bistatic clutter spectrum...
The fractal geometry proved to be the most appropriate mathematical instrument in describing natural scenes, by means of few effective and reliable geophysical parameters. In this paper we describe a complete processing chain for the retrieving of SAR image fractal parameters and for change detection purposes. We present an overall framework employing fractal based models, algorithms and tools to...
This paper introduces innovative SAR system concepts for the acquisition of high resolution radar images with wide swath coverage from spaceborne platforms. The new concepts rely on the combination of advanced multi-channel SAR front-end architectures with novel operational modes. The architectures differ regarding their implementation complexity and it is shown that even a low number of channels...
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...
In this paper we describe a method of processing data from a chosen area as surveyed by a multistatic system for the localization of a target. For this purpose data were acquired using the UCL netted radar and processed with two different incoherent approaches for localizing the target on a grid. The first is a centralized scheme and the second decentralized. Results are compared with two coherent...
In recent work we introduced the notion of diversity in distributed radar systems and we evaluated the diversity order of fully distributed networks. Our long-term goal is to analyze the trade-off between distributed detection and detection using co-located antennas. In this paper, we extend our earlier analysis and we evaluate the diversity of joint detection for symmetric noise-limited systems....
Frequency agility is an important feature when radar operates in jammed environments. With the development of the orthogonal frequency division multiplexing (OFDM) waveform in the communications, the opportunity for a new generation of digital agile radar rises. Old and expensive multi-channel analog agile front ends could be replaced by simpler and cost effective single channel transceivers where...
Orthogonal frequency division multiplexing (OFDM) radar signals, because of their prominent properties have been recently of interest of many researchers. But the large amplitude fluctuations of the OFDM signals makes it susceptible to system nonlinearities. This paper proposes a new concept of radar coding using OFDM signals which combines orthogonal frequency division multiplexing and phase modulation...
In this paper we evaluate the target detection performance improvement of a multi-frequency approach for FM radio based passive bistatic radar. Specifically, we consider the high diversity of the FM radio signals received over different carrier frequencies spanning the 88-108 MHz band since it represents the basis for the request of a multi-frequency operation. The joint exploitation of the waveforms...
Chaff, a typical passive deceivable interference, is commonly used to cheat radar reconnaissance by producing high fidelity echoes in military counter-mission. It is difficult and challenging to distinguish chaff from ship based on their echoes. Firstly a sparseness characteristic analysis is implemented about ship and chaff return in time-domain and frequency-domain, respectively, which conclude...
This work explores the capabilities of cyclostationarity for interference rejection when only one sensor is available. The aim is to detect an unknown signal when it overlaps simultaneously in time and frequency with an interference whose cyclic spectrum is known. The approach is to split separation and detection problems: Firstly, the interference is separated by means of a blind adaptive frequency...
This paper reports on the analysis of technologies opening avenues for potential technological breakthroughs in phased array antennas. We will report on recent results on the insertion of hardware technologies such as RF MEMS and RF Photonics, in the front end of phased array antennas. Future prospects for the insertion of nanotechnologies will be also presented.
In recent years phased arrays have seen breakthroughs that lead to capabilities not possible in the past. This is exemplified by the development of GaAs integrated microwave circuits called monolithic microwave integrated circuits (MMIC). This integration has reached the point where it is possible to now build a low cost 35 GHz phased array for a missile seeker costing $30/element (total cost of array...
This paper describes the COSMO-SkyMed SAR instrument and its active phased array, developed by Thales Alenia Space Italia under contract of Italian Space Agency and Italian Ministry of Defence. Major focus is given to the description of the antenna, the architectural solutions and the technological results.
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...
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