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A high frequency (HF) radar system comprising a skywave transmit channel and surface wave receive channel is studied. Simple analytic expressions for the resolution of this radar system are determined by considering the spreading of radar signals in Doppler and angle during the ionospheric propagation. The detection of ocean surface targets within the patch of ocean surface illuminated by the radar...
The problem of joint transmitter and receiver design for optimum output performance in the context of detection in the presence of clutter and noise is addressed here by maximizing the receiver output signal power to average interference plus noise ratio (SINR) at the specific decision instant. The receiver optimization leads to output SINR in terms of the transmit waveform, and transmitter optimization...
This paper describes a two-step processing procedure which has a capacity of processing bistatic Synthetic Aperture Radar (BSAR) data in the general configuration based on the extended Loffeldpsilas Bistatic Formula (LBF). For LBF, in any configuration, equal contributions to the total azimuth Doppler spectrum are assumed, which results in the failure of LBF in the high bistatic grade configurations...
In this paper, ground penetrating radar and tomography are combined to detect and identify hidden targets, such as underground facilities and hard and deeply buried targets. Past experience in below-ground imaging is described, current measurement results are presented, and future plans are discussed.
Based on Steinpsilas lemma, we use relative entropy as an error exponent measure to study the detection performance of Neyman Pearson (NP) detectors. Both multiple-input-multiple-output (MIMO) radar and phased-array radar are investigated. We introduce the notion of diversity order to get the insights of results. For a bistatic radar where the transmitters and receivers are deployed separately with...
Multi-input multi-output (MIMO) radar is a newly emerging radar system. Based on the diversity of transmitted signals, this paper presents the concept of a distributed multi-channel imaging radar (DMCIR) system. In this system, a set of transmitters and receivers are sparsely located to form multiple signal-processing channels. With the application of matched filtering the orthogonal signals, the...
For some years, there has been an increasing interest in the use of civilian VHF-UHF opportunity transmitters for radar applications. Among the most different civilian broadcasters, analogue FM and Digital transmitters (like Digital Audio Broadcasters and Digital Video Broadcasters) seem to offer interesting capabilities for radar survey according to their availability and/or to their ldquowiderdquo...
Radar detection of cosmic ray air showers has been discussed for 60 years, but never clearly observed. The topic was reexamined by Gorham in 2001 and some serious simulations were done by Takai, who also initiated the Mariachi project utilizing commercial television transmissions as a signal source. The air showers from ultra-high energy cosmic rays are expected to generate a plasma with plasma frequency...
A demonstration of multiple-input multiple-output over-the-horizon radar is presented. Transmitter signal beam- forming on a multi-element array has been created, not conventionally before transmission at the transmitter facility, but, after radar signal transmission, skywave propagation, target scattering, return signal propagation, and reception using an over-the-horizon radar receiver. Transmitter...
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...
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 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 present an overview of the research being carried out by the University of Birmingham in the area of space-surface bistatic radar (SS-BSAR). Global navigation satellite system is considered as the transmitter of opportunity. It also highlights some of the problems faced when a receiver is mounted on a real aircraft. New experimental and imaging results are also presented.
Wireless transmissions are a potentially powerful and widely available source of transmissions for passive radar detection. In this work we have carried out a detailed study on the use of IEEE 802.11 (WiFi) transmissions in a passive radar system. The WiFi transmission sequence has been found to be complex and dependent on the user environment but is dominated by direct sequence spread spectrum (DSSS)...
A signal processing algorithm for ground target detection using forward scattering radar (FSR) is presented in this paper. The effectiveness of the algorithm is shown using both simulated and experimental data. The algorithm is based on the matched filtering approach, where the correlation between the received signal and a set of pre-defined reference functions is calculated. The maximum of the correlation...
Genetic algorithms have proven to be useful tools in optimizing complex problems with large solution spaces. Radar waveform selection is a challenging problem that may benefit from the use of genetic algorithms. Furthermore, advances in the areas of waveform diversity, multistatic radars and knowledge-aided radars are making waveform selection even more challenging. As a design tool we used genetic...
In this paper we consider passive airborne receivers that use backscattered signals from sources of opportunity that transmit fixed-frequency waveforms to form an image of the ground. Due to its combined passive synthetic aperture and fixed-frequency nature of the transmitted waveforms, we refer to the system under consideration as Doppler Synthetic Aperture Hitchhiker (DSAH). We present a novel image...
We derive a new image reconstruction method for distributed apertures operating in complex environments with additive non-stationary noise. Our method is capable of exploiting information that we might have about: multi-path scattering in the environment; statistics of the objects to be imaged; statistics of the additive non-stationary noise. The aperture elements are distributed spatially in an arbitrary...
Traditional radar systems rely on a predefined suite of waveforms and post-measurement signal processing to achieve such goals as target detection, classification, and tracking. Cognitive radar (CR) is a newly proposed framework in which the radar actively interrogates the propagation channel and adapts its operating parameters in order to maximize performance. We apply CR to a target classification...
In this work we investigate rules for sensor placement as a way of improving multistatic radar system performances. We follow the approach of shaping the multistatic ambiguity function, but instead of different weighting rules and different waveforms, as studied in recent works, we consider different system geometries. We concentrate our attention on target resolution as a performance measure and...
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