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The characteristic of low probability of intercept (LPI) radar makes it difficult to intercept with conventional signal intelligence methods so new interception methods need to be devel-oped. This thesis initially describes a simulation of a polytime phase-coded LPI signal. The thesis then introduces a method for classification of LPI radar signals. The method utilizes a parallel tree structure with three separate \"branches\" to exploit the image representation formed by three separate detection methods. Each detection method output is pre-processed and fea-tures are extracted using image processing. After processing the images, they are each fed into three separate neural networks to be classified. The classification output of each neural network is then combined and fed into a fourth neural network performing the final classification. The outcome of testing shows only 53%, which might be the result of the image representation of the detection methods not being distinct enough, the pre -processing/feature extraction not be-ing able to extract relevant information or the neural networks not being properly trained. The thesis concludes with a brief discussion about a suitable method for image processing to extract significant parameters from a LPI signal.

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This thesis investigated five specific phase-shift keyed (PSK) modulated signals for usage in Spotlight Synthetic Aperture Radars (SAR) and the effects each of the individual PSK signals sidelobe structure has on SAR imagery. The specific PSK codes studied were the Frank code, P1 code, P2 code, P3 code and P4 code. A mathematical approach was used to define SAR limitations from signal parameters, and simulations were used to investigate an individual signal parameter’s effects on the sidelobe structure in SAR images. Simulations were used to generate spatially diverse targets, collect each target’s unique echo and apply cross-correlation match filtering and pulse integration to detect each returned echo from the targeted area. Results show the P1 and Frank codes to be the most promising based on the selected parameter presented in this thesis. The P4 code may be better given additional processing to remove range ambiguities, enhancing its unambiguous range.

The book deals with the basic aspects of the statistical theory of detecting radar signals and measuring their parameters in the presence of Gaussian interferences, gives the theory and the principles of designing devices with optimum detection and measuring as well as a great number of examples permitting the reader to familiarize himself more quickly with the main problems of the theory and its applications.

The results of an investigation of analytical and analog techniques for reducing the influence of target support systems for radar scattering measurements are presented. An experimental system for analytically reducing the influence of target supports is implemented by incorporating a phase measurement system and a digital computer into an operational radar cross section measurement facility. Data are obtained by using the system to reduce the influence of the return of Styrofoam support columns during the measurement of 1/2-, 5/8-, 7/8-, and 2-inch diameter spheres and a 30-degree, 5.1-inch diameter sphere-cone as targets at L-Band. A cross section measurement error of about 7 db, resulting from the influence of the target support system, is reduced to about 1 db by using this discrimination system in the vicinity of nose-on in the case of the sphere-cone target. The discrimination system output is compared to a low background measurement on the sphere-cone.

The goal of this thesis is to investigate the effects of an orthogonal frequency-division multiplexing (OFDM) signal versus a linear frequency modulated or chirp signal on simulated synthetic aperture radar (SAR) imagery. Various parameters of the transmitted signal, such as pulse duration, transmitted signal energy, bandwidth, and (specifically for the OFDM signal) number of subcarriers and transmission scheme were examined to determine which parameters are most important to reconstructing a SAR image. Matched filtering and interpolation are two techniques used to reconstruct the SAR image. SAR systems are used in various military and civilian sector applications. Some SAR application examples include ground surveillance, reconnaissance and remote sensing. These applications demand high resolution imagery; therefore, knowledge of exactly which parameters of the transmitted radar signal are more important in producing fine resolution imagery is worth investigating. This research will also aid in providing flexibility in terms of what type of signal and signal parameters are best suited for a particular SAR application and associated military missions. In addition to improving the method attaining high resolution images, SAR process improvement can potentially reduce military SAR system design cost.

This report discusses principles of synthetic aperture radar, properties of radar targets, characteristics of radar imagery, statistical analysis of radar imagery, and the application of modern data analysis.

This report results from a contract tasking Cranfield University (RMCS) as follows: The Grantee will investigate various mathematical concepts of detection and characterization of simulated radar signals. As detailed in the technical proposal at least four approaches will be investigated: 1. A varied matched filter and spectral analysis 2. A neural network (NN) approach based on the use of NNs to detect pulse radar. 3. Methods derived from CDMA (code division multiple access) multiuser detection. 4. Independent component analysis (ICA). He will employ MATLAB and SIMULINK to generate signals and MATLAB for their analysis Efficiency of algorithms will be an important consideration in assessing the performance of the mathematical approaches developed.

This thesis investigated five specific phase-shift keyed (PSK) modulated signals for usage in Spotlight Synthetic Aperture Radars (SAR) and the effects each of the individual PSK signals sidelobe structure has on SAR imagery. The specific PSK codes studied were the Frank code, P1 code, P2 code, P3 code and P4 code. A mathematical approach was used to define SAR limitations from signal parameters, and simulations were used to investigate an individual signal parameter s effects on the sidelobe structure in SAR images. Simulations were used to generate spatially diverse targets, collect each target s unique echo and apply cross-correlation match filtering and pulse integration to detect each returned echo from the targeted area. Results show the P1 and Frank codes to be the most promising based on the selected parameter presented in this thesis. The P4 code may be better given additional processing to remove range ambiguities, enhancing its unambiguous range.

Passive radar systems employing illuminators of opportunity such as commercial television and FM radio signals instead of dedicated radar transmitters have been the subject of increasing interest over the past decade. Under the subject contract funds, components for a flexible passive radar testbed were purchased that allow the exploration of many different passive radar architectures over a wide range of frequencies, from the lower VHF TV band (around 50 MHz) to the lower cell phone band (almost to 1 GHz). Particular emphasis is placed on multiple-antenna passive radar systems employing beamforming, i.e. not just two-antenna interferometry, since beamforming passive radar systems have not been previously explored in academic settings. Extensive technical detail on the components is given, so that this report may also serve as a user's manual for the system.

We develop new time-frequency analytic techniques which facilitate the detection of a person's heart and breath rates from the Doppler shift the movement of their body induces in a terahertz radar signal. One straightforward means of doing such an analysis is the following: take the spectrogram of the ridgeline of the spectrogram of the radar signal. Instead of following this approach exactly, we consider an alternate method in which the ridgeline of the radar signal's spectrogram is replaced with a signal computed from spectral centroids. By using spectral centroids, rather than the ridgeline, we produce a smooth signal that avoids traditional problems with ridgelines, such as jump discontinuities and overquantization. This new method for time-frequency analysis uses a Toeplitz matrix-based algorithm that has a fast Fourier transform-based implementation, and permits centroids of the vertical strips of the spectrogram of the radar signal to be computed without ever having to explicitly compute the spectrogram itself.

The purpose of this study was to determine whether or not it is possible to teach the discrimination between the signals produced by tracked and wheeled vehicles on the AN/TPS-33 radar. Ten junior grade officers received two day's training on twenty tape-recorded exercises. They were given criterion tests at the end of each day of training. The results showed that it is possible to obtain an average performance which is significantly better than chance. (Author)

This report discusses the design of radar signals. It is assumed that the radar receiver is matched to the signal so that the receiver output waveform, in the presence of signal Doppler frequency shift, is characterized by Woodward's two-dimensional signal correlation function. The signal correlation function is discussed, and certain of its properties are collected together. The problem of the detection of a target in the presence of many nearby targets is discussed, and an expression for the target capacity of a radar is developed in terms of the signal correlation function. There follows a discussion of the general problems of signal design for multiple target resolution and for detection of single targets in clutter. Signal waveforms are classified according to the type of modulation, and the design of waveforms of each type is considered in detail. The two-dimensional correlation function is given for each type of signal. Finally, the subject of techniques for generation and reception of signals is discussed.

A new technique for reducing a radar's response to undesired signals entering a radar's sidelobes is described and analyzed theoretically. This technique involves moving the phase center of a phased-array antenna to Doppler-shift sidelobe signals out of the radar receiver's passband. (Author)

A search of scientific literature, both printed and electronic, was undertaken to provide quantitative estimates of attenuation effects of rainfall on weather radar radomes. The emphasis was on C-band (5 cm) and S-Band (10 cm) wavelengths. An empirical model was developed to estimate two-way wet radome losses as a function of frequency and rainfall rate for both standard and hydrophobic radomes. The model fits most of the published data within +/- 1 dB at both target wavelengths for rain rates from less than ten to more than 200 mm/hr. Rainfall attenuation effects remain under 1 dB at both frequencies regardless of radome type for rainfall rates up to 10 mm/hr. S-Band losses with a hydrophobic radome such as that on the WSR-88D remain under 1 dB up to 100 mm/hr. C-Band losses on standard radomes such as that on the Patrick AFB (Air Force Base) WSR-74C can reach as much as 5 dB at 50 mm/hr. In addition, calculations were performed to determine the reduction in effective reflectivity, Z, when a radar target is smaller than the sampling volume of the radar. Results are presented for both the Patrick Air Force Base WSR-74C and the WSR-88D as a function of target size and range.

Spotlight-mode synthetic aperture radar imaging is studied from the viewpoint of tomographic signal processing which allows the relaxation of the nearly-universal assumption that plane waves pass over the ground patch. This allows high-quality image reconstruction in the face of arbitrary amounts of wavefront curvature such as would be present when the angle subtended by the ground patch, as seen by the radar, is not small. One such application is wide- area surveillance. A methodology is used which has the benefits of a wideband transmitted signal (impulse) and a sensible simulation. Image reconstruction algorithms are developed for monostatic and bistatic systems. Simulation results using these algorithms compare favorably with baseline simulations which use a more conventional algorithm operating on data which do not embody the effects of wavefront curvature. Comments on system design and computational implementation are made as necessary. A new set of problems which appear to benefit from the tomographic viewpoint is posed. This work may also find applications in some forms of reflection tomography. (kr)

This article is from Sensors (Basel, Switzerland) , volume 10 . Abstract Different speech detection sensors have been developed over the years but they are limited by the loss of high frequency speech energy, and have restricted non-contact detection due to the lack of penetrability. This paper proposes a novel millimeter microwave radar sensor to detect speech signals. The utilization of a high operating frequency and a superheterodyne receiver contributes to the high sensitivity of the radar sensor for small sound vibrations. In addition, the penetrability of microwaves allows the novel sensor to detect speech signals through nonmetal barriers. Results show that the novel sensor can detect high frequency speech energies and that the speech quality is comparable to traditional microphone speech. Moreover, the novel sensor can detect speech signals through a nonmetal material of a certain thickness between the sensor and the subject. Thus, the novel speech sensor expands traditional speech detection techniques and provides an exciting alternative for broader application prospects.

In book questions of use/application of digital computers for optimum processing of radar signals are examined. Primary attention is given to the detection of signals from the targets, hidden by interferences, and to the determination of the target coordinates. Is described the work of the simplest diagrams of working/treatment, their operating principle, and also work of some nodes of digital computers. Subsequently are given the more complicated cases, special theory and algorithms of working/treatment. Shows how it is realized the synthesis of the structures of machines and their algorithms on the base of the theory of statistical solutions. The necessary information according to the theory of statistical solutions is given on the course of presentation. Book is intended for cabets of military colleges, students of military academies, military engineers and can be used by civil/ civilian specialists, who work in the region of radar.

Information matrices are derived for estimates of the range parameters of moving targets as obtained by combining apriori information (if available with reflected radar signals observed in the presence of additive white Gaussian noise. The inverse of the information matrix provides a lower bound on the covariance matrix of any unbiased parameter estimates. This bound can be approached with a high signal to-noise ratio and optimum data processing (matched filters). Arbitrary frequency modulation, amplitude modulation and target motion as well as various assumptions on processing the R-F phase are considered. The multiple target case enables investigation of a signal's resolution ability as well as its accuracy potentials. Results for a carrier frequency much greater than the effective signal bandwidth are obtained as a special case. A main purpose of the report is the reduction of the original radar problem to a linear model which is equivalent in the sense of having the same information matrix. The various special cases of interest are obtained by simple modifications of the general case and thus the algorithm can provide a very versatile tool for evaluating and designing radar signals.

The acceleration and velocity signal processor developed at the Naval Research Laboratory was employed with the hf transmitter and receiving equipment located at the Chesapeake Bay Division site to observe missiles launched along the Eastern Test Range. The spectral compression and coherent integration techniques utilized in processing the return radar echoes resulted in improved resolution and signal-to-noise ratio, and provided target acceleration as a parameter, along with velocity and range. Target tracks of high definition are shown for the second stages, spent first stages, and nose fairings of ETR tests 0169 (Saturn) and 3670 (A3 Polaris).

The use and processing of the FM/CW signal for radar and acoustic sounder systems are examined. This signal--along with real-time digital processing via minicomputers--is currently being used by several groups for HF over-the-horizon radars. A comparative analysis of the different processing techniques for general radar applications has yet to be undertaken. This note therefore attempts to promulgate details of these techniques so that they may find use in other systems. An example involving an HF backscatter radar is used to permit the reader to see how the technique are applied to an actual problem.

This thesis provides a method for determining the detection of partially correlated Rayleigh distributed radar returns by a pulsed search radar. The receiver consists of a quadrature demodulator receiver, followed by a square law envelope detector and a linear post-detection integrator. In addition, a technique for determining the pulse-to-pulse correlation of a complex target is given using inverse Fourier transforms of the target scattering centers. An AIM-9 missile is used to illustrate how the partially correlated detection techniques and the pulse-to-pulse correlation predictions can be used to determine the probability of detection. The Detection and Correlation Modeling of Rayleigh Distributed Radar Signals.

China May Jam US Radar Signals In South Korea

The requirements for an optimal sequence for SuperDARN radar are stated. Obtained quasioptimal signals up to 26-pulse sequence are based on optimal and nearly optimal Golomb rulers. It is shown that standard 7-pulse SuperDARN sequence is one of the quasioptimal sounding signals, but 8-pulse kascan SuperDARN signal is not. The characteristics are calculated for quasioptimal sounding sequences up to 26-pulse one. It is shown that the most effective signals for the spectral measurements are 10, 12, 14, 18, 20, 24 and 26 pulse sequences. We present the results of the first spectral measurements at the EKB SuperDARN radar with quasioptimal 8- and 9-pulse sequences, as well as with the optimal 10-and 12-pulse sequences. A comparison with the results obtained with standard 7-pulse SuperDARN sequence were made. The continuity of results in amplitude and velocity is shown, the expected improvement in the spectral width are also demonstrated.

Several on line and off line data processing techniques are used to remove interfering signals due to ground clutter, aircraft, instrumental effects, and external transmissions from the desired atmospheric echoes of Mesosphere Stratosphere, Troposphere (MST) radar. The on line, real time techniques are necessarily simple in order to minimize processing delays. This algorithm examines the individual Doppler spectra which are computed every two to four seconds (for oblique antenna beams). The total spectral power in each individual spectrum is computed by summing all the spectral points. If this integrated power increases from one spectrum to the next by a factor greater than a preselected threshold, then that spectrum is not added to the spectral sum. Succeeding spectra are compared to the last acceptable spectrum. Only a certain maximum number of spectra are allowed to be rejected in succession.

The detection of ultra-wide-band (UWB) radar signals is considered. Conventional radar theory is examined in the context of ultrawideband signals and extended when necessary. Point target detectors are found for the cases when the additive interference is white Gaussian noise and correlated Gaussian noise or clutter. A conventional moving target indicator (MTI) design is generalized for UWB radar. The effects of bandwidth on the resolution of clutter and target are examined. Optimal and conventional processing are compared for single echo detection. An optimal detector is found for a distributed target with a known target profile. Additionally, optimal detectors are found under two models where only second-order statistics of the target profile are assumed known. Future work areas are suggested. Detection, Ultra-wide-band, Radar

This thesis applies time-frequency transformations to radar signals. Specifically, it considers the feasibility of applying time-frequency transformations to extract the intra-pulse modulation parameters of radar signals. In this work, we consider radar signals with analog pulse compression; specifically linear or hyperbolic intra-pulse modulation. Several time-frequency transformations are investigated to identify which one gives the most accurate image representation for signals in noisy environments. Next, image processing techniques are applied in conjunction with an adaptive curve fitting method, for the hyperbolic modulation scheme, to extract the parameters of the frequency equation. Results show that for the linear chip case the frequency equation can be estimated with small error down to SNR equal to -10dB. The proposed method for the hyperbolic chirp modulation is less immune to noise degradation and it can be used down to SNR level equal to 2dB.

Among the numerous problems which arise in the context of radar signal processing is the problem of extraction of information from a noise corrupted signal. In this application the signal is assumed to be the superposition of outputs from multiple radar emitters. Associated with the output of each emitter is a unique set of parameters which are in general unknown. Significant parameters associated with each emitter are (1) the pulse repetition frequencies, (2) the pulse durations (widths) associated with pulse trains and (3) the pulse amplitudes. A superposition of the outputs of multiple emitters together with additive noise is observed at the receiver. In this study we consider the problem of decomposing such a noise corrupted lin- ear combination of emitter outputs into an underlying set of basis signals while also identifying the parameters associated with each of the emitters involved. Foremost among our objectives is to design a system capable of performing this decomposition/classification in a demanding real-time environment. We present here a system composed of three cascaded neural-analog networks which, in simulation, has demonstrated an ability to nominally perform the task of decomposition and classification of superposed radar signals under extremely high noise conditions.

The power spectra S(f) of MST radar signals contain useful information about the variance of refractivity fluctuations, the mean radial velocity, and the radial velocity variance in the atmosphere. When noise and other contaminating signals are absent, these quantities can be obtained directly from the zeroth, first and second order moments of the spectra. A step-by-step procedure is outlined that can be used effectively to reduce large amounts of MST radar data-averaged periodograms measured in range and time to a parameterized form. The parameters to which a periodogram can be reduced are outlined and the steps in the procedure, that may be followed selectively, to arrive at the final set of reduced parameters are given. Examples of the performance of the procedure are given and its use with other radars are commented on.

To measure operator proficiency in identifying audio signals from the AN/TPS-33 ground surveillance radar, a test of 120 tape-recorded signals generated by representative military targets was administered to 43 trained operators. It was found that they could discriminate between personnel and vehicle targets. An experiment was run to determine whether operators can be trained to identify vehicles on the basis of signal characteristics unique to each vehicle type. After two days' training, 10 naive officer subjects learned to discriminate reliably between tracked and wheeled vehicles, although there were marked differences in operator aptitude.

Reduction of Side Lobes of Radar signals for Complementary Code using Particle Swarm Optimization

A three-dimensional ray-tracing code has been developed to run in conjunction with the University of Alaska polar ionospheric model. The ionospheric model may be run in a real-time predictive mode and its outputs have been used as an input to the ray tracing code. The objective of this work is to compute refractive effects on UHF radar signals due to time-varying ionospheric structures at high latitudes. Radar range and pointing errors are calculated continuously during two 24-hour periods in this paper to demonstrate the effects from a time-varying ionosphere during quiet and moderately disturbed geomagnetic conditions. Radar pointing errors that correspond to target errors up to about 500m have been found for low antenna elevation radar pointing directions during moderately disturbed geomagnetic conditions.

A three-dimensional ray-tracing code has been developed to run in conjunction with the University of Alaska polar ionospheric model. The ionospheric model may be run in a real-time predictive mode and its outputs have been used as an input to the ray tracing code. The objective of this work is to compute refractive effects on UHF radar signals due to time-varying ionospheric structures at high latitudes. Radar range and pointing errors are calculated continuously during two 24-hour periods in this paper to demonstrate the effects from a time-varying ionosphere during quiet and moderately disturbed geomagnetic conditions. Radar pointing errors that correspond to target errors up to about 500m have been found for low antenna elevation radar pointing directions during moderately disturbed geomagnetic conditions.

In this report we present a statistical model for the signals of an acousto-optic spectrum analyzer (AOSA). Using the model, we calculate the Cramer-Rao bound for the estimation of the carrier frequency of radar signals and the performance of the peak detector estimator. We also present an algorithm for sidelobe rejection. Canada.

The term Low Probability of Intercept (LPI) is that property of an emitter that because of its low power, wide bandwidth, frequency variability, or other design attributes, makes it difficult to be detected or identified by means of passive intercept devices such as radar warning, electronic support and electronic intelligence receivers. In order to detect LPI radar waveforms new signal processing techniques are required. This thesis first develops a MATLABʼ toolbox to generate important types of LPI waveforms based on frequency and phase modulation. The power spectral density and the periodic ambiguity function are examined for each waveform. These signals are then used to test a novel signal processing technique that detects the waveform parameters and classifies the intercepted signal in various degrees of noise. The technique is based on the use of parallel filter (sub-band) arrays and higher order statistics (third-order cumulant estimator). Each sub-band signal is treated individually and is followed by the third-order estimator in order to suppress any symmetrical noise that might be present. The significance of this technique is that it separates the LPI waveform in small frequency bands, providing a detailed time-frequency description of the unknown signal. Finally, the resulting output matrix is processed by a feature extraction routine to detect the waveform parameters. Identification of the signal is based on the modulation parameters detected.

Bell System Technical Journal, 46: 8. October 1967 pp 1753-1773. Communications and Radar Receiver Gains for Minimum Average Cost of Excluding Randomly Fluctuating Signals in Random Noise. (Rappaport, Stephen S.)

A microwave radar signal is generated for transmission through an antenna. Before transmission, the signal is phase modulated by 0 deg or 90 deg amounts during each alternate half-cycles of an intermediate frequency (IF) clock signal. After transmission and return, the signal is again phase modulated the same amounts during each alternate half-cycles. The return phase modulated signal is mixed with a leakage signal component of the microwave signal, leaving an IF Doppler. The IF Doppler signal may then be amplified, removing any requirement that direct current level signals be amplified and also removing the effect of detector noise from the Doppler signal.

The effect of coherent integration on the periodogram method to estimate the power spectra of MST radar signals is examined. The spectrum estimate usually is biased, even when care is taken to reduce the aliasing effects. Due to this bias, the signal power for Doppler shifted signals is underestimated by as much as 4 dB. The use of coherent integration in reducing the effect of aliased power line harmonics is pointed out.

A longstanding performance goal for Army ground surveillance radars is the automatic classification of moving ground targets on the battlefield. Limited classification has been achieved by splitting the radar doppler spectrum into lower and higher frequency bands, thus distinguishing between targets having different radial velocities. While this is an important feature, since only certain targets (vehicles) are capable of obtaining high radial speeds, it does not provide a distinction between a moving man and vehicles having low radial speed components. That there are distinct differences in the doppler signatures between man and vehicle is easily established by listening to typical doppler return signals. One can clearly distinguish the step modulation of a walking man from the relatively constant or slowly changing tone of a vehicle. As to be expected, a spectrogram of a walking man shows this repetitive behavior. Most obvious is a sinewave like frequency modulation at the step frequency of the main body return power appearing as a black band near 100 Hertz. This oscillatory temporal characteristic in the doppler shifted frequency is practically never seen in vehicular return and is the discriminant chosen for automatic classification.

Compressive sensing (CS) has received considerable research interest recently. CS has been successfully applied in many applications, such as high-resolution image processing, wireless communication, electronic signal capturing and biomedical imaging systems [1]. In the context of radar, the number of potential targets is often limited. Hence, exploiting the sparsity of radar signals in various spaces, CS has been recently applied to multiple-input multiple-output (MIMO) radar systems.

ADA738877

This report investigates the bispectral processing of complex-valued radar target scattering signatures and the impact of such processing on target identification. The concept of 'birange profile' as two-dimensional display of target scattering mechanisms in the range domain is introduced. It is shown that the birange profile can detect responses due to multiple scattering interactions. An algorithm is proposed to estimate the birange profiles of radar targets. Using this algorithm, multiple interactions of real aircraft are extracted, and interpreted in terms of target geometry. An algorithm that uses autoregressive parametric modeling of radar signatures to obtain high resolution birange profiles was introduced and tested using synthesized data and real scattering data. An alternative estimation procedure, which does produce the true bispectrum, was developed. The classification aspect of birange features was investigated using cross-correlation of birange profile of unknown target with that of a catalog target. It was shown that classification using birange features is inferior to classification using impulse response features if the additive noise is Gaussian. Classification with the birange when the noise is non-Gaussian yields relatively reasonable results in comparison with other classifiers. Finally, it was shown that when scattering from extraneous point scatterers is added to the data, then classification with the birange outperforms other classifiers if the signal-to-extraneous scatterers ration is low. Keywords: Identification, Signal processing, Targets, Radar, Statistical.

This report discusses the study phase of the terminal radar-beacon fiber optics remoting project. Fiber optics technology is discussed and applied to the remoting of airport surveillance radar (ASR) and air traffic control beacon interrogator (ATCBI) video and control signals. The requirements of this system are outlined and an engineering model, using multiplexed and nonmultiplexed video transmissions, is specified for installation at the Federal Aviation Administration (FAA) Technical Center. Tests to be conducted on this system are briefly outlined. Cost estimates are presented as well as suggested sources of supply fort the fiber optic components. The interface to the ASR and ATCBI systems is described. It is recommended that the system be built by the technical center. A schedule for completion of the remainder of the project is presented. (Author)

This thesis investigates advanced processing techniques for the detection of radar targets in the presence of clutter. It is assumed that the radar data available consist of multi-aspect angle, fully polarimetric Synthetic Aperture Radar (SAR) images. Various techniques are introduced and tested on available SAR data. These techniques attempt to exploit the multi-aspect angles in order to extract target characteristics not available in any single image. SAR images are manipulated in such a way to decrease the probability of false alarms in the target detection process. Target detection performance of the techniques is presented and compared. The techniques are shown to give superior results than that of regular SAR.

This note is a preliminary study of radar signals viewed as discretised nonlinear dynamical systems. Motivated by [Haykin and Li 1995], a class of recursively defined signals is introduced, and two specific examples are considered. It will be shown that such signals can exhibit complex dynamics in phase space. This means that they experience sensitive dependence on initial conditions. Using the Lyapunov spectrum, we determine the stability of these signals. We will also investigate whether such signals are of practical use in radar by examining their ambiguity functions.

A consortia was formed in 1984 to tackle the subject of automatically finding and identifying specified objects in a complicated environment from two dimensional images. The consortia members consist of four industrial partners - British Aerospace, Marconi Command and Control Systems, Standard Telecommunications Laboratories and The Royal Signals and Radar Establishment - and three universities - Bristol, Reading and Surrey. The project began in 1985 and now in 1989 is almost completed. This report describes the RSRE contribution to the MMI007 project. Great Britain. (rrh)

The characteristic of low probability of intercept (LPI) radar makes it difficult to intercept with conventional signal intelligence methods so new interception methods need to be developed. This thesis initially describes a simulation of a polytime phase-coded LPI signal. The thesis then introduces a method for classification of LPI radar signals. The method utilizes a parallel tree structure with three separate 'branches' to exploit the image representation formed by three separate detection methods. Each detection method output is pre-processed and features are extracted using image processing. After processing the images, they are each fed into three separate neural networks to be classified. The classification output of each neural network is then combined and fed into a fourth neural network performing the final classification. The outcome of testing shows only 53%, which might be the result of the image representation of the detection methods not being distinct enough, the pre -processing/feature extraction not being able to extract relevant information or the neural networks not being properly trained. The thesis concludes with a brief discussion about a suitable method for image processing to extract significant parameters from a LPI signal.

Generalized multivariate analysis of variance and related reduced-rank regression are general statistical models that comprise versions of regression, canonical correlation, and analyses, as well as analysis of variance (ANOVA) and covariance in univariate and multivariate settings. It is a powerful and yet not very well known tool. In 1 we develop a unified framework for explaining, analyzing, and extending signal processing methods based on GMANOVA. We show the applicability of this framework to a number of detection and estimation problems in signal processing and communications, and provide new and simple ways to derive numerous existing algorithms for: 1) radar target estimation and detection; 2) source location using parametric signal models; 3) synchronization and space-time channel and noise estimation; 4) space-time symbol detection in 5) blind channel equalization, estimation, and signal separation; 6) spectral analysis nuclear magnetic resonance (NMR) spectroscopy. Many of the above methods were originally derived from scratch, without knowledge of their close relationship with the GMANOVA model. We explicitly show this relationship and present new insights and guidelines for generalizing these methods. We also acknowledge the pioneering works of Brillinger (on frequency-wave number analysis, and Kelly and Forsythe (on radar detection, who first applied GMANOVA to signal processing problems. Our results could inspire applications of the general framework of GMANOVA to new problems in signal processing. We present such an application to flaw detection in nondestructive evaluation (NDE) of materials. A promising area for future growth is image processing.

LPI radar is a class of radar systems that possess certain performance characteristics that make them nearly undetectable by today's digital intercept receivers, This presents a significant tactical problem in the battle space To detect these types of radar, new digital receivers that use sophisticated signal processing techniques are required This thesis investigates the use of cyclostationary processing to extract the modulation parameters from a variety of continuous-wave (CW) low-probability-of- intercept (LPI) radar waveforms, The cyclostationary detection techniques described exploit the fact that digital signals vary in time with single or multiple periodicities, because they have spectral correlation, namely, non-zero correlation between certain frequency components, at certain frequency shifts, The use of cyclostationary signal processing in a non-cooperative intercept receiver can help identify the particular emitter and can help develop electronic attacks, LPI CW waveforms examined include Frank codes, polyphase codes (Pt through P4), Frequency Modulated CW (FMCW), Costas frequencies as well as several frequency-shift-keying/phase-shift-keying (FSK/PSK) waveforms It is shown that for signal-to-noise ratios of OdB and -6 dB, the cyclostationary signal processing can extract the modulation parameters necessary in order to distinguish among the various types of LPI modulations.

1Voyage Towards the South Pole and Round the World Volume 1

By James Cook

Having, on his first voyage, discovered Australia, Cook still had to contend with those who maintained that the Terra Australians Incognita (the unknown Southern Continent) was a reality. To finally settle the issue, the British Admiralty sent Cook out again into the vast Southern Ocean with two sailing ships totalling only about 800 tons. Listen as Cook, equipped with one of the first chronometers, pushes his small vessel not merely into the Roaring Forties or the Furious Fifties but becomes the first explorer to penetrate the Antarctic Circle, reaching an incredible Latitude 71 degrees South, just failing to discover Antarctica. (Introduction by Shipley)

LibriVox volunteers bring you 16 recordings of Be Kind When You Can by Eliza Cook. This was the Weekly Poetry project for January 30, 2011.<br><br>Eliza Cook was an English author, Chartist poet and writer born in London Road, Southwark.<br><br>She was the daughter of a local tradesman. She attended the local Sunday Schools and was encouraged by the son of the music master to produce her first volume of poetry. From this she took confidence and in 1837 began to offer verse to the radical Weekly Dispatch, then edited by William Johnson Fox. She was a staple of its pages for the next ten years. She also offered material to The Literary Gazette, Metropolitan Magazine and New Monthly. (summary from Wikipedia)

3Life of Florence Nightingale, Volume 1

By Edward Tyas Cook

A history of Florence Nightingale (1820-1910), the founder of modern nursing. Here's the definitive biography, gleaned from a lifetime of her notes, letters and writings, that goes way beyond the mere legend of "The Lady With The Lamp", and the "Founder Of Modern Nursing". This well written saga covers the vastly more expanded story of her development into an intelligent woman with a high purpose, her social standing and family connections that opened many doors for her, her extensive work after the Crimean War working with governments to develop better health care delivery systems to the indigent in England and in India, and her voluminous writings on numerous topics. Volume 1 recounts her life from childhood through 1861. (Summary by Michele Fry)

4Life of Florence Nightingale, Volume 2

By Edward Tyas Cook

A history of Florence Nightingale (1820-1910), the founder of modern nursing. Here's the definitive biography, gleaned from a lifetime of her notes, letters and writings, that goes way beyond the mere legend of "The Lady With The Lamp", and the "Founder Of Modern Nursing". This well written saga covers the vastly more expanded story of her development into an intelligent woman with a high purpose, her social standing and family connections that opened many doors for her, her extensive work after the Crimean War working with governments to develop better health care delivery systems to the indigent in England and in India, and her voluminous writings on numerous topics. Volume 2 recounts her life from 1861 through her death in 1910. (Summary by Michele Fry)

The first of 3 voyages of Captain Cook - this one is to New Zealand and the South Pacific. - Summary by Lynda Marie Neilson

6Adrift in the Unknown; or Queer Adventures in a Queer Realm

By William Wallace Cook

A delightful, imaginative, and sometimes silly adventure in early science fiction. Join a noble scientist and some of his less noble associates as they take flight in a newly constructed, seemingly magical spaceship. After they land on the planet Mercury, they are caught in the crossfire in a war between futuristic Mercurean city-states which wield high-tech weaponry. As they fight for their own survivial and that of their fellow humans, each man is challenged to confront his own moral failings. Set aside your 21st-century knowledge of physics and settle in for a lighthearted, somewhat predictable romp through outer space. - Summary by Amanda Rumbaugh

7Voyage Towards the South Pole and Round the World Volume 2

By James Cook

Having disproved the myth of Terra Australis Incognita (The unknown Southern Continent), Cook returns to New Zealand via the Friendly Islands, Easter Island, Norfolk Island, New Caledonia, and Vanuatu. Cook then returns home via Cape Horn, discovering South Georgia and the South Sandwich Islands before putting into Cape Town to refit before finally sailing home. Volume 2 also includes the Journal of Captain Furneaux during the period when he was separated from Captain Cook - Summary by David Cole

8First Voyage of James Cook Volume 1

By James Cook

In May 1768, the Admiralty commissioned the 39-year old Cook to command a scientific voyage to the Pacific Ocean to observe and record the 1769 transit of Venus across the Sun. The expedition sailed aboard HMS Endeavour in August 1768, rounded Cape Horn and continued to Tahiti, where the observations of the transit were made. Cook then opened sealed orders for the second part of his voyage: to search the south Pacific for signs of the postulated rich southern continent of Terra Australis. Cook proceeded to circumnavigate New Zealand's two main islands, which is where this volume ends. - Summary by David Cole

9First Voyage of James Cook Volume 2

By James Cook

Following his discovery and circumnavigation of New Zealand recorded in Volume 1, Cook sailed westwards to Australia, whose east coast was at that time unknown. After initially sighting Port Hicks, Cook landed at Botany Bay, where he tried but failed to make contact with the native inhabitants. He proceeded northward, mapping about a thousand miles of coastline and discovering the Great Barrier Reef by severely damaging his ship in running into one of the reefs. The ship was in danger of sinking and limped to the mainland where, over a period of seven weeks, major repairs were made by the ship's crew. Cook then proceeded to Cape York, the northern tip of Australia and completed his circumnavigation of the globe via Batavia (modern Jakarta, Indonesia), the Cape of Good Hope and St. Helena. - Summary by David Cole

10Third Voyage of James Cook, Volume 1

By James Cook

Only months after his return from his mammoth Second Voyage, the Admiralty ordered Cook back to the Pacific, ostensibly to return Omai, a young man from Raiatea, to his homeland, but in fact to attempt the discovery of the Northwest Passage (a proposed route from the Pacific to the Atlantic north of Canada). Cook commanded HMS Resolution and was accompanied by Captain Clerke commanding HMS Discovery. After sailing to the Pacific via Tenerife, Cape Town and New Zealand, Omai was returned to his home, after which Cook became the first European to visit the Sandwich Islands (Hawaii) and then mapped the West Coast of North America. After many delays, he penetrated the Bering Strait, but was unable because of ice to proceed either East or West. He eventually returned to Hawaii, where Cook was killed by the natives. Following the death of Captain Clerke from tuberculosis, the ships eventually returned to Britain under the command of Captain Gore. This first volume covers only the portion of the voyage up to the first visit to Hawaii. - Summary by David Cole

Only months after his return from his mammoth Second Voyage, the Admiralty ordered Cook back to the Pacific, ostensibly to return Omai, a young man from Raiatea, to his homeland, but in fact to attempt the discovery of the Northwest Passage (a proposed route from the Pacific to the Atlantic north of Canada). Cook commanded HMS Resolution and was accompanied by Captain Clerke commanding HMS Discovery. After sailing to the Pacific via Tenerife, Cape Town and New Zealand, Omai was returned to his home, after which Cook became the first European to visit the Sandwich Islands (Hawaii) and then mapped the West Coast of North America. After many delays, he penetrated the Bering Strait, but was unable because of ice to proceed either East or West. He eventually returned to Hawaii, where Cook was killed by the natives. Following the death of Captain Clerke from tuberculosis, the ships eventually returned to Britain under the command of Captain Gore. This second volume covers the portion of the voyage from leaving Tonga, sailing through the Bering Strait and attempting to find a Northwest or Northeast passage, and sailing to Hawaii, up to immediately before Cook's death there. (Summary by David Cole)

From the darkest corners of the Amazon to the idyllic island paradise of Borneo, the early years of Weird Tales were chocked full of dread tales of jungle terrors. Fierce beasts, deadly cannibals and all other manner of unknown horrors await beneath the lush canopies of trees. Even if you aren't foolish enough to brave the dangers of the jungle, the jungle may come to you instead! Join us for another fright-filled collection of stories from the celebrated halls of Weird Tales magazine! - Summary by Ben Tucker