Download or read book Spectral Characteristics of Radar Target Returns in Clutter written by Herman V. Cottony and published by . This book was released on 1970 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: The results of further investigation into the possibility of resolving radar targets in clutter, using spectral approach, are described. Characteristics of back-scatter returns by ground-clutter scatterers consisting of seven non-resonant scatterers are examined in the frequency domain. It is seen that, when the scatterers are of equal magnitude and are equally spaced in range, the returns, in the frequency domain, are characterized by lobes of relatively high amplitude separated by gaps in frequency spectrum where the amplitude is relatively low. A mathematical analogy to the radiation pattern of an array antenna is pointed out. Three quasi-random ground-clutter models were designed, using tables of random digits. The returns from these models, measured in the frequency domain, were recorded and compared with the computed results. Taking into account the differences between the assumed conditions and the conditions found at the range, the agreement is found satisfactory. Three cases of backscatter radar models consisting of one or two non-resonant target scatterers in quasi-random clutter models were investigated. As a result, it appears that the search for hidden target scatter may be simplified if a searching pulse, with time delay varying linearly with time, is injected into the system. (Author).
Download or read book Optimal Spectrum Filtering for the Radar Detection of Targets in Clutter written by John K. Schindler and published by . This book was released on 1969 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: A novel radar technique is proposed for detecting the presence of a target having a priori known frequency-dependent scattering properties. The target coexists with a large collection of clutter elements having random scattering properties and ranges. Assuming a wideband random signal excitation, the power spectrum of the scattered field consists of the target return having an a priori known frequency behavior embedded in a clutter return having a random frequency dependence. On an ensemble average basis, the clutter appears as additive noise from which the existence of a prescribed target return must be extracted.
Download or read book Radar Signature Analysis of Indoor Clutter and Stationary Human Target Classification written by Travis Bufler and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Research in through-the-wall radar (TTWR) is a recent area of focus and as such many challenges have arisen related to target detection, location, and tracking. These types of radar systems are often plagued by harsh clutter scenarios caused by the variety and abundance of furniture elements within the antenna's field-of-view which in turn degrade the radars ability to accurately detect targets. Furthermore, once an object is located, having the ability to identify the object under consideration is still an on ongoing research problem. This dissertation has two main focuses. The first analyzes and investigates the spectral signatures of indoor clutter elements through their radar cross section (RCS). The characterization of the wideband spectral properties for indoor clutter elements is accomplished using finite difference time domain (FDTD) techniques. Using FDTD, the spectral characteristics of clutter elements were obtained over a wide range of frequencies and aspect angles at different transmit-receive polarization combinations. The spectral properties are then compared and contrasted between the different objects as well as human biological models for analysis and use in TTWR. The RCS results obtained from the simulations are then compared to experimental data collected using a wideband network analyzer. The second main topic is the use of machine learning algorithms, specifically Support Vector Machines (SVMs) to construct models from the previously acquired spectral signatures to aid in target classification. Utilizing variables of frequency and polarization, a SVM classifier can be constructed to classify unknown targets as either human or clutter object. Additionally, the application of feature selection algorithms are applied to the spectral characteristics to reduce the model complexity and determine the SVM classification accuracy of a reduced dataset. Finally, the classification performance is assessed in the presence of additive white Gaussian noise (AWGN) and through various wall materials.
Download or read book Spectral Characteristics of Low angle Radar Ground Clutter written by and published by . This book was released on 1989 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: The performance of ground-based radars is affected by the spectral characteristics of ground clutter. Most signal processing algorithms designed to enhance detection performance are Doppler-frequency-sensitive, such as the moving target indicator filter, Doppler processor and coherent clutter map. This report gives the results of a comprehensive spectral analysis of low-angle ground clutter, using the MIT Lincoln Laboratory Phase I data and the DREO S-band clutter data. The report presents the spectral analysis of ground clutter for different bands of radar frequency; describes the data used in the spectral analysis, including both the conventional Fourier analysis and a super-resolution spectral analysis technique; gives a brief background on the maximum entropy spectral estimate; and describes the particular procedure designed to bring out the spectral characteristics of ground clutter from short time series.
Download or read book Optimal Spectrum Filtering for the Radar Detection of Targets in Clutter written by John K. Schindler and published by . This book was released on 1969 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A novel radar technique is proposed for detecting the presence of a target having a priori known frequency-dependent scattering properties. The target coexists with a large collection of clutter elements having random scattering properties and ranges. Assuming a wideband random signal excitation, the power spectrum of the scattered field consists of the target return having an a priori known frequency behavior embedded in a clutter return having a random frequency dependence. On an ensemble average basis, the clutter appears as additive noise from which the existence of a prescribed target return must be extracted.
Download or read book Radar Ground Clutter Measurement and Models Part 2 Spectral Characteristics and Temporal Statistics written by Hing C. Chan and published by . This book was released on 1991 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: The performance of ground-based surveillance radars is affected by the spectral characteristics and the temporal statistics of ground clutter. Traditionally, ground clutter problems are treated by employing filtering techniques such as delay-line cancellers. These techniques result in a degraded detection performance of low-velocity targets. With the worsening congestion in air traffic, there is an increased demand for improved performance of low-velocity target detection. To improve the detection performance of ground-based surveillance radars for low-velocity targets, signal processing algorithms which exploit ground-clutter characteristics must be developed. This requires a thorough understanding of ground-clutter behaviour. In this paper, we report the results of the spectral and statistical analyses of low-angle ground clutter, using data of the MIT Lincoln Laboratory Phase I program and S-band coherent ground-clutter data collected by the Radar Division of the Defence research Establishment Ottawa. The results of the spectral analysis show that ground clutter, as observed by a coherent radar with a stationary antenna, comprises three components: (a) a coherent component, (b) a slow-diffuse component and (c) a fast-diffuse component. These components can be described by relatively simple models. The model parameters are functions of radar frequency, waveform resolution, land cover and wind speed.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 836 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Millimeter wave Radar Targets and Clutter written by Gennadiĭ Petrovich Kulemin and published by Artech House. This book was released on 2003 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt: This ground-breaking resource offers you a detailed treatment of EDGE and its critical role in the development of the mobile Internet. The book explains how this global radio based high-speed mobile data standard can be introduced into GSM/GPRS networks, improving data transmission speeds to support multimedia services. It enables you to become thoroughly knowledgeable of EDGE specifications and covers concepts pertaining to several domains, including RF, signal processing, digital communications and communication networks.
Download or read book Academic Press Library in Signal Processing written by Fulvio Gini and published by Academic Press. This book was released on 2013-09-10 with total page 1389 pages. Available in PDF, EPUB and Kindle. Book excerpt: This second volume, edited and authored by world leading experts, gives a review of the principles, methods and techniques of important and emerging research topics and technologies in communications and radar engineering. With this reference source you will: Quickly grasp a new area of research Understand the underlying principles of a topic and its application Ascertain how a topic relates to other areas and learn of the research issues yet to be resolved Quick tutorial reviews of important and emerging topics of research in array and statistical signal processing Presents core principles and shows their application Reference content on core principles, technologies, algorithms and applications Comprehensive references to journal articles and other literature on which to build further, more specific and detailed knowledge Edited by leading people in the field who, through their reputation, have been able to commission experts to write on a particular topic
Download or read book Principles of Integrated Maritime Surveillance Systems written by A. Nejat Ince and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt: Information is always required by organizations of coastal states about the movements, identities and intentions of vessels sailing in the waters of interest to them, which may be coastal waters, straits, inland waterways, rivers, lakes or open seas. This interest may stem from defense requirements or from needs for the protection of off-shore resources, enhanced search and rescue services, deterrence of smuggling, drug trafficking and other illegal activities and/or for providing vessel traffic services for safe and efficient navigation and protection of the environment. To meet these needs it is necessary to have a well designed maritime surveillance and control system capable of tracking ships and providing other types of information required by a variety of user groups ranging from port authorities, shipping companies, marine exchanges to governments and the military. Principles of Integrated Maritime Surveillance Systems will be of vital interest to anyone responsible for the design, implementation or provision of a well designed maritime surveillance and control system capable of tracking ships and providing navigational and other types of information required for safe navigation and efficient commercial operation. Principles of Integrated Maritime Surveillance Systems is therefore essential to a variety of user groups ranging from port authorities to shipping companies and marine exchanges as well as civil governments and the military.
Download or read book Radar Return from Targets Hidden by Ground Clutter written by Werner W. Gerbes and published by . This book was released on 1967 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: A theoretical solution to the problem of radar return from objects hidden by ground clutter is formulated in this report. The solution is based on a model in which metal targets are simulated by the substitution of metal for the ground. A comparison of the returned signal from the simulated target with the returned signal from the earth is obtained, and calculated values are graphically presented for various values of dielectric constants, conductivities, and depth of clutter. (Author).
Download or read book Atmospheric Effects on Radar Target Identification and Imaging written by H. Jeske and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Advanced Study Institute (ASI) under discussion was initiated by the "Special Programme Panel on Radio meteorology" of the Scientific Affairs Division of NATO. The domain of this panel - and consequently the topics of their former ASI-~rogrammes - is the influ ence of the non-ionized atmosphere on electromagnetic wave propagation, its prediction and its use as a re mote sensing technique. It is the final goal to inform radio and radar engineers about the various defects caused by the propagation medium atmosphere. Today there exist high-sensitive radar systems which can pro vide identification and produce images of distant ob jects very accurately by measuring a) the effect of the target on the shape of a short radar pulse, or b) the wave front (phase and amplitude distribution) and its orientation in space. But usuallv the radar-to-target path is through the inhomogeneous and turbulent atmo sphere and so the absolut limits of the system are very often determined by this atmosphere. It was the plan of this ASI to arrange an interdisciplinary information exchange between radar experts and propagation specia lists in order to get a better understanding of the susceptibility to atmospheric effects and to develope new methods that will reduce or correct these errors. The lectures given and especially the intensive dis cussions during the workshop sessions contributed to this aim.
Download or read book A Note on Resolution of Radar Targets in Clutter written by Herman V. Cottony and published by . This book was released on 1973 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt: The paper describes exploratory work towards resolution of radar returns in clutter which involves the analysis of the frequency spectrum of the return. However, the technique employed makes use of power spectrum without the phase information.
Download or read book Introduction to Radar Target Recognition written by P. Tait and published by IET. This book was released on 2005 with total page 428 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book text provides an overview of the radar target recognition process and covers the key techniques being developed for operational systems. It is based on the fundamental scientific principles of high resolution radar, and explains how the underlying techniques can be used in real systems, taking into account the characteristics of practical radar system designs and component limitations. It also addresses operational aspects, such as how high resolution modes would fit in with other functions such as detection and tracking.
Download or read book Report of NRL Progress written by Naval Research Laboratory (U.S.) and published by . This book was released on 1961 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Study of Clutter Reduction Techniques in Wide Bandwidth HF VHF Deep Ground Penetrating Radar written by Darien J. Hammett and published by . This book was released on 2002-08-01 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reducing clutter is one of the most daunting problems a radar processing engineer faces. Clutter causes a significant problem when attempting to detect sub-surface targets, as any significant change in the ground dielectric will produce a return at the receiver. The difficulty in reducing the clutter is compounded by the fact that the spectral characteristics of the clutter are similar to that of the target. While there are many methods that exist to reduce clutter, few do not require a prior information of either the target or the clutter. There are applications, of interest to the electromagnetic community, that are restricted in the amount of a prior information available to them. Estimation-subtraction filters calculate an estimate of the clutter from the statistics of the data collected and subtract that estimate from the original data. The Wiener filter has long been used as a way to suppress noise signals when a target reference is known. Using it to reduce clutter is a relatively new area of research. This research proposes estimation-subtraction filters and an application of the Wiener filter, which do not require a priori information to reduce the clutter of a bi-static synthetic aperture based, wideband deep ground penetrating radar system. The results of applying these filters to data collected in this way, at these depths, are illustrated here for the first time.
