Academic literature on the topic 'Monopulse'

University of Central Florida College of Engineering Thesis<br>High Resolution Radar techniques are applied to the problem of resolving a multiple target array and locating its geometric center without the usual biasing toward the brightest targets. Monopulse radar techniques are combined with high resolution stepped frequency pulse train signal processing in an amplitude tracking radar. A single pulse monopulse system's aimpoint is biased toward the brightest point targets in an array. However, by using a stepped frequency pulse monopulse radar, the cross range distance to each individual scatterer may be found. Unlike the single pulse monopulse system, the aimpoint is independent of the reflectivity of the targets. The geometric center of a multiple scatterer array is found by averaging the cross range components along both axes. For the stepped frequency high resolution monopulse system, the center of each uniquely separated pair of point targets is calculated by examining the cross-correlation function of the sum and difference channels. The autocorrelation of the sum channel is used to normalize the cross-correlation data thereby eliminating the effects of the different targets radar cross sections (RCS). The zero separation term of the error function (DC term) remains biased toward the bigger scatterer, even after normalization. The nonzero terms (AC terms) are the cross range distances from the antenna's boresight to each scatterer and are independent of their RCS. By simply dropping ones together, the aimpoint becomes the unbiased geometric center of the array. The special cases of one, two and three resolvable point scatterers are examined in detail. Analysis of a nondiscrete complex scattering array is not presented, since the requirement of separation pair uniqueness cannot be assumed. The monopulse tracking simulation work was done on an IMB AT using Microsoft Fortran-77.<br>M.S.<br>Masters<br>Engineering<br>Engineering<br>105 p.<br>v, 105 leaves, bound : ill. ; 28 cm.

An analysis and simulation tool is developed for optimizing system parameters of the monopulse target tracking radar and observing effects of the system parameters on the performance of the system over different scenarios. A monopulse tracking radar is modeled for measuring the performance of the radar with given parameters, during the thesis studies. The radar model simulates the operation of a Class IA type monopulse automatic tracking radar, which uses a planar phased array. The interacting multiple model (IMM) estimator with the Probabilistic Data Association (PDA) technique is used as the tracking filter. In addition to modeling of the tracking radar model, an optimization tool is developed to optimize system parameters of this tracking radar model. The optimization tool implements a Genetic Algorithm (GA) belonging to a GA Toolbox distributed by Department of Automatic Control and System Engineering at University of Sheffield. The thesis presents optimization results over some given optimization scenarios and concludes on effect of tracking filter parameters, beamwidth and dwell interval for the confirmed track.

As part of the processing of tracking targets, surveillance radars detect the presence of targets and estimate their locations. This dissertation re-examines some of the often ignored practical considerations of radar tracking. With the advent of digital computers, modern radars now use sampled versions of received signals for processing. Sampling rates used in practice result in the bin-straddling phenomenon, which is often treated as an undesired loss in signal power. Here, a signal model that explicitly models the sampling process is used in the derivation of the average loglikelihood ratio test (ALLRT), and its detection performance is shown to defeat the bin-straddling losses seen in traditional radar detectors. In monopulse systems, data samples are taken from the sum and difference channels, by which a target direction-of-arrival (DOA) estimate can be formed. Using the same signal model, we derive new estimators for target range, strength, and DOA and show performance benefits over traditional monopulse techniques that are predominant in practice. Since tracking algorithms require an error variance report on target parameter estimates, we propose using the generalized Cramer-Rao lower bound (GCRLB), which is the CRLB evaluated at estimates rather than true values, as an error variance report. We demonstrate the statistical efficiency and variance consistency of the new estimators. With several parameter estimates collected over time, tracking algorithms are used to compute track state estimates and predict future locations. Using agile- beam surveillance radars with programmable energy waveforms, optimal scheduling of radar resources is a topic of interest. In this dissertation, we focus on the energy management considerations of tracking highly maneuverable aircraft. A comparison between two competing interacting multiple model (IMM) filter configurations is made, and a recently proposed unbiased mixing procedure is extended to the case of three modes. Finally, we introduce the radar management operating curve (RMOC), which shows the fundamental tradeoff in radar time and energy, to aid radar designers in the selection of an overall operating signal-to-noise level.

This master’s thesis covers the design and implementation of a monopulse directionof arrival (DOA) estimation algorithm on an FPGA. The goal is to implement a complete system that is capable of estimating the bearing of an incident signal. In order to determine the estimate quality both a theoretical and practical noise analysis of the signal chain is performed. Special focus is placed on the statistical properties of the transformation from I/Q-demodulated signals with correlated noise to a polar representation. The pros and cons for three different methods of calculating received signal phasors are also covered.The system is limited to two receiving channels which constrains this report to a 2D analysis. In addition the used hardware is limited to C-band signals. We show that an FPGA implementation of monopulse techniques is definitely viable and that an SNR higher than ten dB allows for a gaussian approximation of the polar representationof an I/Q signal.

International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California<br>Three-channel monopulse tracking receiver systems are commonly used for high performance tracking of satellites, missiles, or aircraft to maximize the reception of data. Typically, the receiver in such systems are custom designed for their end purpose. This results in a high cost to cover the development, service, and support of a highly specialized piece of equipment. This paper covers the requirements and performance of a 3-channel monopulse tracking receiver assembled from commercial-off-the-shelf (COTS) equipment. Such a system provides an option for designing or upgrading tracking stations with the lower cost, larger support base, and greater system configuration choices that are available with COTS equipment.

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2006.<br>This thesis documents the design and implementation of an S-band receiver for phasecomparison monopulse radar. The design and evaluation of the various sub-systems involved in realizing the receiver are discussed in detail. The designed sub-systems are connected via low loss coaxial cables to form the complete phase-comparison monopulse radar receiver. The performance of the receiver is evaluated and compared with the theoretical results, in terms of frequency response, gain and noise figure. The designed receiver is finally connected to an existing antenna system, and a preliminary test of the complete radar is performed. The initial results show that the design is successful, but the boresight-axis of the radar has shifted in angle and requires pre-comparator phase shifting in order to obtain accurate tracking. ii

Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1999.<br>Includes bibliographical references (leaves 76-78).<br>Sound localization has been the subject of much ongoing research in the area of beam­formers and microphone arrays. Although these methods have been successful under certain conditions, the signal processing requirements needed for real-time operation are extensive. This thesis describes the construction and test of a piezoelectric monopulse direction­finding sensor used to determine the angular location of a source within the plane of the sensor. The design of the sensor exploits spatially derivative-matched sensing apertures to eliminate angle ambiguities and frequency dependence of the monopulse ratio. The electronics front end and processing are very simple, consisting of averag­ing the sample-by-sample ratios of the rectified-and-smoothed outputs during their reverberation-free time period. Several experiments are described with different inputs, and the sensor's operation is compared to theoretical and simulated behavior. Although the effects of the hexcell support on the spatial weighting of the sensor are not fully understood, it is shown that the sensor behaves as a dispersionless monopulse sensor for an angular range of ± 40° and a bandwidth of 4 kHz. It is also shown that the sensor does not, in its current form, produce adequate signal levels to be used as a speech localization device.<br>by Phillip James Rowe.<br>M.Eng.

This master thesis investigates how certain components error margin may affect the accuracy of a IFF monopulse receiver. The IFF monopulse receiver measures the angle of arrival of the incident signal by comparing sum and difference signals created in the receiver. The components of interest are phase shifters and attenuators, where both can give individual and different errors depending on the antenna steering angle. The project is conducted at Saab Aeronautics, based on a receiver in development for the Gripen E aircraft. The results of the thesis generated results showing that the angular accuracy decreases with the increase of steering angle. The angular deviation can for some cases be seen as sufficiently small for the receiver to work properly in the ideal case.