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# Communications, Radar and Signal Processing, IEE Proceedings F

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• ### Digital beam forming for radar

Publication Year: 1980, Page(s):266 - 277
Cited by:  Papers (2)
| | PDF (1353 KB)

Development of digital methods for antenna beam forming in the receiving mode of a radar can be advantageous in providing the system with a high degree of flexibility in beam-pattern managementÂ¿ for countering e.c.m. and providing multiple functions efficiently. The justification for incorporating digital methods and various possible arrangements are discussed first. The main body of the paper i... View full abstract»

• ### Digital signal processing for target detection FMCW radar

Publication Year: 1981, Page(s):331 - 336
Cited by:  Papers (3)
| | PDF (717 KB)

The paper describes a method of digital signal processing for extracting and isolating targets in the return signal of an FMCW radar. Digital filtering of the frequency spectrum of the return signal is followed by nonlinear optimisation to detect the presence of multiple targets amid clutter. Results using a practical radar show that the method gives enhanced detection of weak return signals. View full abstract»

• ### Adaptivity and design criteria of a latest-generation MTD processor

Publication Year: 1985, Page(s):58 - 65
Cited by:  Papers (4)
| | PDF (875 KB)

A latest-generation or adaptive¿¿ moving target detector (A-MTD) digital processor is described. The A-MTD is based on three banks of filters, to cope with different levels of ground clutter. The paper includes: (i) the technique for the filter design, (ii) the trade-off for the number of bits to represent the filter coefficients (iii) some of the obtained filtering performances (iv) the analysis... View full abstract»

• ### A complex gradient operator and its application in adaptive array theory

Publication Year: 1983, Page(s):11 - 16
Cited by:  Papers (30)
| | PDF (673 KB)

The problem of minimising a real scalar quantity (for example array output power, or mean square error) as a function of a complex vector (the set of weights) frequently arises in adaptive array theory. A complex gradient operator is defined in the paper for this purpose and its use justified. Three examples of its application to array theory problems are given. View full abstract»

• ### The geometry of bistatic radar systems

Publication Year: 1986, Page(s):604 - 612
Cited by:  Papers (23)
| | PDF (1056 KB)

Unless the separation between transmitter and receiver is small compared with ranges of interest, bistatic radars have a number of properties which differ significantly from the monostatic equivalents. Some of these produce operational advantages which provide a motivation for deployment, while others merely bring trouble and expense. The paper considers the basic bistatic properties which depend ... View full abstract»

• ### Maximum entropy method in image processing

Publication Year: 1984, Page(s):646 - 659
Cited by:  Papers (1)
| | PDF (1827 KB)

Maximum entropy has proved to be an enormously powerful tool for reconstructing images from many types of data. It has a privileged position as the only consistent method for combining different data into a single image. It has been used most spectacularly in radio astronomical interferometry, where it deals routinely with images of up to a million pixels, and high dynamic range. We also give exam... View full abstract»

• ### Design and performance of airborne radomes: a review

Publication Year: 1981, Page(s):451 - 464
Cited by:  Papers (4)
| | PDF (1773 KB)

The ever increasing demands on the performance of airborne antennas place comparable demands on the design of the enclosing randome to ensure minimal degradation of the antenna radiation pattern. Radomes for airborne application can be separated into three main categories: large aircraft radomes of either the nose-cone or under-fuselage type, small aircraft radomes often flush mounted to the airfr... View full abstract»

• ### Introduction to electronic warfare

Publication Year: 1982, Page(s):113 - 132
Cited by:  Papers (7)
| | PDF (3554 KB)

The paper discusses the overall concept of electronic warfare (EW) and defines its three main subsets: electronic support measures (ESM), electronic countermeasures (ECM) and electronic counter-countermeasures (ECCM). The requirements for ESM receivers are reviewed in the context of two specific scenarios: that of intelligence gathering for communications and radar. The different current ESM recei... View full abstract»

• ### Intercept time and its prediction

Publication Year: 1985, Page(s):215 - 220
Cited by:  Papers (6)
| | PDF (927 KB)

Intercept time is a key factor in the performance of electronic warfare (EW) surveillance and reconnaissance equipments. Interception relates to the probability of time coincidence of two or more parametric windows; scanning antennas, sweeping or stepping receivers and frequency-agile emitters give examples of such windows, where alignment or coincidence is required before detection can occur. For... View full abstract»

• ### Theory of radar detection in coherent Weibull clutter

Publication Year: 1987, Page(s):174 - 190
Cited by:  Papers (9)
| | PDF (1847 KB)

The paper deals with the problem of radar detection of a target echo embedded in Weibull clutter and white Gaussian noise (WGN). Relevant features of the paper, with respect to previous papers on the same subject, refer to the coherent nature of the Weibull process (that modelling the clutter) and of the processing chain. In more detail, the in-phase and quadrature components of the clutter echoes... View full abstract»

• ### Waveform design and doppler sensitivity analysis for nonlinear FM chirp pulses

Publication Year: 1986, Page(s):163 - 175
Cited by:  Papers (1)
| | PDF (1251 KB)

The use of pulse compression to obtain simultaneous long-range detection and good range resolution is described. The types of modulation that can be used to obtain pulse compression are outlined with particular emphasis on their performance under Doppler shift. It is shown that nonlinear frequency-modulated (FM) signals are capable of providing low range-sidelobes while being compressed using a ma... View full abstract»

• ### Characterisation of radar clutter as a spherically invariant random process

Publication Year: 1987, Page(s):191 - 197
Cited by:  Papers (82)
| | PDF (1028 KB)

A statistical characterisation of clutter as a complex random process is needed in the design of optimum detection schemes. The paper considers modelling complex clutter as a spherically invariant random process (SIRP), namely assuming that its PDFs can be expressed as non-negative definite quadratic forms, a generalisation of a Gaussian process. Relevant properties of SIRPs are summarised, and sh... View full abstract»

Publication Year: 1982, Page(s):133 - 137
| | PDF (661 KB)

The paper describes a broadband crystal video receiver, optimised for use in radar warning receivers with a direction-finding capability. The system design and the technologies adopted have been chosen to obtain a small, light and reliable line-replaceable unit that requires no particular adjustment to interface with other circuits. The receiver features a frequency-band-sorting capability to impr... View full abstract»

• ### Use of metric techniques in ESM data processing

Publication Year: 1985, Page(s):229 - 232
Cited by:  Papers (12)
| | PDF (424 KB)

The paper describes the use of metric techniques in an electronic support measures (ESM) data processing scheme developed at Smith Associates Consulting System Engineers Limited for the UK Ministry of Defence (Procurement Executive). The ESM data processing scheme takes in digital pulse data describing the radar pulses illuminating an ESM receiver. The output from the scheme is a continuously upda... View full abstract»

• ### Effect of Fresnel ripples on sidelobe suppression in low time-bandwidth product linear FM pulse compression

Publication Year: 1982, Page(s):41 - 44
Cited by:  Papers (10)
| | PDF (457 KB)

The paper discusses the effects of Fresnel ripples on the suppression of peak time sidelobes in low time-bandwidth (TB) product linear-FM pulse compression systems employing internally Hamming weighted compression filters. Two methods for the reduction of these effects are investigated. The first, amplitude tapering of the rectangular FM pulse, yields significantly diminished sidelobes for TB prod... View full abstract»

• ### Singular-value decomposition approach to time series modelling

Publication Year: 1983, Page(s):202 - 210
Cited by:  Papers (19)
| | PDF (1182 KB)

In various signal processing applications, as exemplified by spectral analysis, deconvolution and adaptive filtering, the parameters of a linear recursive model are to be selected so that the model is most¿¿ representative of a given set of time series observations. For many of these applications, the parameters are known to satisfy a theoretical recursive relationship involving the time series' ... View full abstract»

• ### Jaguar-V frequency-hopping radio system

Publication Year: 1982, Page(s):213 - 222
Cited by:  Papers (6)
| | PDF (1363 KB)

The electronic threat to VHF tactical communications systems is reviewed, and possible counter-measures are discussed. The principles of the Jaguar-V frequency-hopping system are described, together with some aspects of the radio-system design and technical features of its implementation. Operational aspects of system performance are also discussed. View full abstract»

Publication Year: 1986, Page(s):649 - 657
Cited by:  Papers (50)
| | PDF (1311 KB)

The paper discusses the use of illuminators of opportunity¿¿ for bistatic radar systems. Experiments in the London area using the Crystal Palace transmitters are reported, including the use of TV pictures designed to make the transmission more closely resemble a pulsed radar signal. It is shown that the separation of targets from the direct signal and clutter requires extensive signal processing ... View full abstract»

• ### Chaff

Publication Year: 1982, Page(s):197 - 201
Cited by:  Papers (1)
| | PDF (714 KB)

The paper reviews the development of chaff as an electronic-countermeasures (ECM) technique and describes the basic principles of chaff as reflectors of radar waves. The various common types of chaff are described, including their main physical and aerodynamic characteristics. Some illustration of the use of chaff is given in naval and airforce applications. View full abstract»

• ### Introduction to subsurface radar

Publication Year: 1988, Page(s):278 - 320
Cited by:  Papers (34)
| | PDF (8750 KB)

Subsurface radar techniques are increasingly being used for the detection and location of buried artefacts and structures within the upper regions of the earth's surface. The paper reviews the work done to date in this field, laying emphasis on the range of applications and the need for system design to match the intended application. An overall design strategy is outlined, together with a more de... View full abstract»

• ### Fifty years of bistatic and multistatic radar

Publication Year: 1986, Page(s):596 - 603
Cited by:  Papers (1)
| | PDF (1262 KB)

The article begins with a review of the history of bistatic and multistatic radars, including the simultaneous introduction of radar technology in several countries during the 1930s and the various areas of technology development pursued by those countries. Technical descriptions are presented of nine different experimental systems. The article continues with a discussion of the potential military... View full abstract»

• ### Cell-averaging CFAR for multiple-target situations

Publication Year: 1986, Page(s):176 - 186
Cited by:  Papers (8)
| | PDF (1027 KB)

The performance of a mean-level detector is considered when one or more interfering target returns is present in the set of cells used in estimating the reference level. A serious degradation of detection probability is demonstrated for Swerling target fluctuation models 1 and 3. To alleviate the problem we analyse an alternative procedure. A censoring scheme is proposed whereby samples exceeding ... View full abstract»

• ### Design techniques and performance of digital IFM

Publication Year: 1982, Page(s):154 - 163
Cited by:  Papers (7)
| | PDF (1542 KB)

The digital instantaneous-frequency-measuring receiver using delay-line discriminators was developed in the early 1960s specifically as a wideband and accurate analyser of pulsed radar signals. Various receiver configurations are incorporated in most of the more comprehensive EW systems currently in use. In the paper, the basic operating principles and design philosophy are reviewed, together with... View full abstract»

• ### Overview of detection theory in multistatic radar

Publication Year: 1986, Page(s):613 - 623
Cited by:  Papers (11)
| | PDF (1262 KB)

The detection problem with multistatic radar systems is considered, resorting to the theory of detection of coherent target signals having a Gaussian probability density embedded in coherent Gaussian-distributed disturbances (i.e. clutter and/or directional jamming). A novelty of the paper is related to the capability of dealing with any type of time autocorrelation function of both target and dis... View full abstract»

• ### Radar detection prediction in sea clutter using the compound K-distribution model

Publication Year: 1985, Page(s):613 - 620
Cited by:  Papers (36)
| | PDF (945 KB)

In the paper the radar detection of targets in sea clutter modelled by the compound K-distribution is examined from a statistical detection viewpoint. Optimum performance is determined for both fixed threshold and ideal constant false alarm rate (CFAR) receivers for targets modelled by Swerling cases 0, 1 and 2. In particular, the performance of dual threshold binary integrators is assessed. The c... View full abstract»

• ### Spatial correlation in K-distributed sea clutter

Publication Year: 1987, Page(s):526 - 532
Cited by:  Papers (24)
| | PDF (921 KB)

The compound K-distribution model for sea clutter previously described in the literature provides the foundation for a quantitative treatment of the spatial and temporal correlation characteristics of the envelope of clutter returns. In the paper the compound K-distribution model is extended to cover the spatial characteristics of sea clutter. The relationship of these characteristics to the physi... View full abstract»

• ### ESM processor system for high pulse density radar environments

Publication Year: 1985, Page(s):621 - 625
Cited by:  Papers (8)
| | PDF (692 KB)

A radar ESM system performs two functions: warning of impending threats and surveillance to determine radar activities. Automatic radar ESM systems are passive radar receivers which receive emissions from other platforms, measure the parameters of each pulse received and thus sort the emissions to enable determination of the radar parameters for each emitter. These parameters are then compared wit... View full abstract»

• ### DC coefficient restoration in transform image coding

Publication Year: 1984, Page(s):709 - 713
Cited by:  Papers (9)
| | PDF (561 KB)

In a transform coding system, a large number of bits have to be allocated to high-energy DC coefficients for both fine quantisation and good channel error immunity. Three schemes are proposed, in which the DC coefficients are not transmitted, but estimated at the receiver. This allows a reduction in bit rate, as well as the possibility of eliminating the serious effect of channel errors on those c... View full abstract»

• ### Suspended substrate stripline filters for ESM applications

Publication Year: 1985, Page(s):257 - 266
Cited by:  Papers (3)
| | PDF (1315 KB)

Multi-octave contiguous channel multiplexers are a key component in EW systems, since they provide the front-end signal sorting. The paper describes advances in the development of broadband, low-loss, selective, lowpass, highpass and bandpass filters and contiguous channel multiplexers from 500 MHz to 26.5 GHz, in the form of suspended substrate stripline (SSS) realisations in particular to increa... View full abstract»

• ### Graph theory for image analysis: an approach based on the shortest spanning tree

Publication Year: 1986, Page(s):146 - 152
Cited by:  Papers (46)
| | PDF (1183 KB)

The paper describes methods of image segmentation and edge detection based on graph-theoretic representations of images. The image is mapped onto a weighted graph and a spanning tree of this graph is used to describe regions or edges in the image. Edge detection is shown to be a dual problem to segmentation. A number of methods are developed, each providing a different segmentation or edge detecti... View full abstract»

• ### Survey of radar data-processing techniques in air-traffic-control and surveillance systems

Publication Year: 1980, Page(s):190 - 204
Cited by:  Papers (9)
| | PDF (2080 KB)

The application of data-filtering techniques for air-traffic-control and surveillance systems is re-reviewed. Operational requirements of these systems are primarily described. They are typically composed of radars (mechanical scanning and phased array), data-processing devices (digital computers) and displays. The environment is determined by the number and characteristics of targets and by the d... View full abstract»

• ### Distributed radar detection theory

Publication Year: 1986, Page(s):55 - 60
Cited by:  Papers (60)
| | PDF (660 KB)

A theory of the distributed detection of radar targets is developed. The radar system employs a number of physically separated peripheral receivers and detectors and a central processor that provides a final decision by combining peripheral decisions rather than decision statistics. Various combining strategies are studied in the context of overall system optimality. It is shown that the optimal d... View full abstract»

• ### Power spectral density of digital continuous phase modulation with correlated data symbols. Part 1: Autocorrelation function method

Publication Year: 1986
Cited by:  Papers (2)
| | PDF (1239 KB)

A general method for computing the power spectral density (PSD) of an encoded, continuous phase modulated (CPM) signal with correlated data symbols is presented in the paper. The encoder is a finite-state sequential machine which introduces correlation between symbols transmitted in different time slots. The method used is the so-called autocorrelation function method, in which the autocorrelation... View full abstract»

• ### Application of efficient linear FM matched filtering algorithms to synthetic aperture radar processing

Publication Year: 1985, Page(s):45 - 57
Cited by:  Papers (53)
| | PDF (1716 KB)

The applicability of two relatively new linear FM matched filtering algorithms to the processing of synthetic-aperture radar (SAR) data is examined and compared to the fast-convolution algorithm. The algorithms, called basic spectral analysis and the step transform, use the properties of the linear FM signal to achieve some significant performance improvements. The algorithms are evaluated on the ... View full abstract»

• ### New method for generating frequency modulation

Publication Year: 1981, Page(s):135 - 139
| | PDF (694 KB)

The paper describes how asynchronons delta sigma modulation can be used to generate frequency modulation. Present FM modulators have an inherent nonlinearity in the voltage/frequency characteristic, and as a consequence they are restricted to small percentage frequency deviations. The ADSM-FM modulator is inherently linear, allowing a wide percentage frequency deviation to be obtained. When incorp... View full abstract»

• ### High-frequency sonar transducers: a review of current practice

Publication Year: 1984, Page(s):285 - 297
| | PDF (1647 KB)

The paper is a review of current design and constructional practice of conventional high-frequency transducers which make use of piezoelectric plates and discs. The main design technique is based on the concept of the equivalent circuit, and to emphasise the design techniques three contemporary designs of increasing sophistication are detailed. The problems likely to be encountered are discussed. ... View full abstract»

• ### Assessment of timing jitter in digital telecommunications transmission systems

Publication Year: 1987, Page(s):464 - 473
Cited by:  Papers (1)
| | PDF (1461 KB)

The topics of jitter origin, accumulation and control are vitally important in digital systems and networks, and form an important part of the relevant performance specifications. The principal properties of jitter are summarised and the philosophy behind current international specifications explained. A review of measurement requirements and techniques for testing the jitter performance of digita... View full abstract»

Publication Year: 1982, Page(s):180 - 186
Cited by:  Papers (2)
| | PDF (1047 KB)

The choice of transform parameters for SAW radar intercept is dictated by the limitations of available digital output stages and by the nature of the input signal, rather than by limitations imposed by the surface-acoustic-wave components. The choice of parameters needed to design a radar-intercept compressive receiver for use in a pulsed-signal environment is discussed, as is the resulting `trade... View full abstract»

• ### Automatic processing for ESM

Publication Year: 1982, Page(s):164 - 171
Cited by:  Papers (13)
| | PDF (1677 KB)

In the past, radar ESM systems have relied on operator interpretation of measured parameters to provide classification and identification of emitters. However, for rapid response in the dense electromagnetic environments encountered in modern warfare, automatic processing and decision-making techniques are required. In order to identify individual emitters, their pulse trains must be deinterleaved... View full abstract»

• ### Sidescan sonar

Publication Year: 1984, Page(s):243 - 256
Cited by:  Papers (11)
| | PDF (2591 KB)

The paper starts with a review of sidescan imagery and the history of sidescan sonar and continues with the acoustic and technical factors affecting the sonar design for any specified application. There follows a description of present-day applications in the civilian field, and the paper ends with discussion of possible future developments. View full abstract»

• ### Comparison between steepest descent and LMS algorithms in adaptive filters

Publication Year: 1987, Page(s):283 - 289
Cited by:  Papers (1)
| | PDF (713 KB)

It is commonly stated that the least-mean-square (LMS) algorithm for adaptive filters is a stochastic version of the steepest descent (SD) optimisation technique, although little work on comparative studies has been reported. The present paper sets out a detailed theoretical and experimental comparison. Equations are derived for the directional variance of the estimated gradient, and these are the... View full abstract»

• ### Tracking function in bistatic and multistatic radar systems

Publication Year: 1986, Page(s):630 - 637
Cited by:  Papers (8)
| | PDF (852 KB)

The paper presents a unified view of the tracking algorithms available for multistatic radar systems. The first topic considered is the derivation of tracking algorithms for bistatic radar. Different algorithms can be conceived according to different sets of measurements which may be processed (e.g. the range sum and one angle, or two angles). Mean and standard deviation values of tracking errors ... View full abstract»

• ### Adaptive array processing. A tutorial

Publication Year: 1983
| | PDF (746 KB)

An array is defined as a set of sensors, for example antennas or acoustic transducers. The outputs from these sensors can be processed in an adaptive manner to respond to an unknown interference environment in an attempt to optimise the performance of the system in some defined manner. The paper is intended as an introduction to, and to some extent a survey of, some of the methods used in adaptive... View full abstract»

• ### MSK and offset QPSK signal transmissions through nonlinear satellite channels in the presence of intersymbol interference

Publication Year: 1983, Page(s):513 - 518
Cited by:  Papers (1)
| | PDF (645 KB)

An expression is derived for the bit error probability of minimum shift keying (MSK) and offset quaternary phase shift keying (OQPSK) signals which have been transmitted through nonlinear satellite channels after bandlimiting. The transponder nonlinearity considered in the paper is of the bandpass type, which exhibits AM/AM and AM/PM conversion effects. The effects of up-link and down-link thermal... View full abstract»

• ### Eclipsing effects with high-duty-factor waveforms in long-range radar

Publication Year: 1985, Page(s):598 - 603
Cited by:  Papers (7)
| | PDF (637 KB)

The partial eclipsing of returns in long-range radar with a high-duty-factor waveform is considered, and two eclipsing zones are shown to exist. The effects on clutter levels, by virtue of increased range sidelobes, and on signal/noise ratio, pulsewidth and pulse amplitude are examined. It is shown that the enhancement of range sidelobes caused by eclipsing, and the associated clutter effects, do ... View full abstract»

• ### Communications security. A survey of cryptography

Publication Year: 1982
| | PDF (132 KB)

Our society has become highly dependent on its modern communications systems, e.g. the radio, television, telephone, telex, facsimile, high-speed data links etc. A high proportion of the information disseminated over these communications circuits is confidential in nature. In these situations the communicants should take steps to conceal the content of a message from not only the casual listener b... View full abstract»

• ### Tracking systems for satellite communications

Publication Year: 1988, Page(s):393 - 407
Cited by:  Papers (11)
| | PDF (2247 KB)

Satellites in nominally geostationary orbits possess diurnal motion which causes the apparent position of the spacecraft to wander in the sky as seen by an earth station. If uncompensated this causes a variation in the performance of the communications link. The motion of the satellite therefore has to be tracked by the earth station antenna. During the past twenty years or so a considerable amoun... View full abstract»

• ### Signal sorting in ESM systems

Publication Year: 1985, Page(s):226 - 228
Cited by:  Papers (8)
| | PDF (402 KB)

As radar signal environments become denser and radar signals become more complex, the task of an ESM operator becomes more difficult. In environments where the numbers of radars may be large and the number of pulses transmitted by a radar may be small, the operator becomes the dominating factor in the efficiency of an ESM system. The paper discusses the problem of developing automatic sorting of r... View full abstract»

Publication Year: 1983, Page(s):433 - 440
Cited by:  Papers (2)
| | PDF (767 KB)

The paper describes a new procedure for designing linear adaptive arrays with a controllable broadband capability. The new prodecure allows acceptable array performance to be achieved without the need for broadband presteering delays. The approach relies on the use of a special array weight vector constraint involving |w|. Convergent algorithms for solving the new broadband design procedure are de... View full abstract»

• ### New angle-of-arrival estimator: comparative evaluation applied to the low-angle tracking radar problem

Publication Year: 1988, Page(s):408 - 420
| | PDF (1945 KB)

This paper examines a new, fast, highperformance angle-of-arrival (AOA) estimator called the QR-based spectrum estimation algorithm, which we apply to the low-angle tracking problem in radar. We compare the performance of this algorithm to the more established modern estimators of its kind; namely, the MUSIC and modified FBLP algorithms. This comparison is based on real data collected from an expe... View full abstract»