MATLAB simulations for radar systems design

686 Pages·2004·14.159 MB·English

by  Elsherbeni, Atef Z., Mahafza, Bassem R

Simulations for
Radar Systems
Design
Bassem R. Mahafza, Ph.D.
Decibel Research, Inc.
Huntsville, Alabama
Atef Z. Elsherbeni
Professor
Electrical Engineering Department
The University of Mississippi
Oxford, Mississippi
CHAPMAN & HALL/CRC
A CRC Press Company
Boca Raton London New York Washington, D.C.
© 2004 by Chapman & Hall/CRC CRC Press LLC
C3928_disclaimer Page 1 Wednesday, November 5, 2003 1:36 PM
Library of Congress Cataloging-in-Publication Data
Mahafza, Bassem R.
MATLAB simulations for radar systems design / Bassem R. Mahafza, Atef
Z. Elsherbeni
p. cm.
Includes bibliographical references and index.
ISBN 1-58488-392-8 (alk. paper)
1. Radar–Computer simulation. 2. Radar–Equipment and
supplies–Design and construction–Data processing. 3. MATLAB. I.
Elsherbeni, Atef Z. II. Title
TK6585.M34 2003
621.3848′01′13—dc22 2003065397
This book contains information obtained from authentic and highly regarded sources. Reprinted material
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© 2004 by Chapman & Hall/CRC CRC Press LLC
To: My wife and four sons;
Wayne and Shirley;
and
in the memory of my parents
Bassem R. Mahafza
To: My wife and children;
my mother;
and
in the memory of my father
Atef Z. Elsherbeni
© 2004 by Chapman & Hall/CRC CRC Press LLC
Preface

The emphasis of (cid:147)MATLAB Simulations for Radar Systems Design(cid:148) is on
radar systems design. However, a strong presentation of the theory is provided
so that the reader will be equipped with the necessary background to perform
radar systems analysis. The organization of this book is intended to teach a
conceptual design process of radars and related trade-off analysis and calcula-
tions. It is intended to serve as an engineering reference for radar engineers
working in the field of radar systems. The MATLABfi1 code provided in this
book is designed to provide the user with hands-on experience in radar sys-
tems, analysis and design.
A radar design case study is introduced in Chapter 1 and carried throughout
the text, where the authors(cid:146) view of how to design this radar is detailed and
analyzed. Trade off analyses and calculations are performed. Additionally, sev-
eral mini design case studies are scattered throughout the book.
(cid:147)MATLAB Simulations for Radar Systems Design(cid:148) is divided into two parts:
Part I provides a comprehensive description of radar systems, analyses and
design. A design case study, which is carried throughout the text, is introduced
in Chapter 1. In each chapter the authors(cid:146) view of how to design the case-study
radar is presented based on the theory covered up to that point in the book. As
the material coverage progresses through the book, and new theory is dis-
cussed, the design case-study requirements are changed and/or updated, and of
course the design level of complexity is also increased. This design process is
supported by a comprehensive set of MATLAB 6 simulations developed for
this purpose. This part will serve as a valuable tool to students and radar engi-
neers in helping them understand radar systems, design process. This includes
1) learning how to go about selecting different radar parameters to meet the
design requirements; 2) performing detailed trade-off analysis in the context of
radar sizing, modes of operations, frequency selection, waveforms and signal
processing; 3) establishing and developing loss and error budgets associated
with the design; and 4) generating an in-depth understanding of radar opera-
tions and design philosophy. Additionally, Part I includes several mini design
case studies pertinent to different chapters in order to help enhance understand-
ing of radar design in the context of the material presented in different chap-
ters.
Part II includes few chapters that cover specialized radar topics, some of
which is authored and/or coauthored by other experts in the field. The material
1. MATLAB is a registered trademark of the The MathWorks, Inc. For product infor-
mation, please contact: The MathWorks, Inc., 3 Apple Hill Drive, Natick, MA
01760-2098 USA. Web: www.mathworks.com.
© 2004 by Chapman & Hall/CRC CRC Press LLC
included in Part II is intended to further enhance the understanding of radar
system analysis by providing detailed and comprehensive coverage of these
radar related topics. For this purpose, MATLAB 6 code has also been devel-
oped and made available.
All MATLAB programs and functions provided in this book can be down-
loaded from the CRC Press Web site (www.crcpress.com). For this purpose,
follow this procedure: 1) from your Web browser type (cid:147)http://www.crc-
press.com(cid:148), 2) click on (cid:147)Electronic Products(cid:148), 3) click on (cid:147)Download &
Updates(cid:148), and finally 4) follow instructions of how to download a certain set
of code off that Web page. Furthermore, this MATLAB code can also be down-
loaded from The MathWorks Web site by following these steps: 1) from your
Web browser type: (cid:147)http://mathworks.com/matlabcentral/fileexchange/(cid:148), 2)
place the curser on (cid:147)Companion Software for Books(cid:148) and click on (cid:147)Communi-
cations(cid:148). The MATLAB functions and programs developed in this book
include all forms of the radar equation: pulse compression, stretch processing,
matched filter, probability of detection calculations with all Swerling models,
High Range Resolution (HRR), stepped frequency waveform analysis, ghk
tracking filter, Kalman filter, phased array antennas, clutter calculations, radar
ambiguity functions, ECM, chaff, and many more.
Chapter 1 describes the most common terms used in radar systems, such as
range, range resolution, and Doppler frequency. This chapter develops the
radar range equation. Finally, a radar design case study entitled (cid:147)MyRadar
Design Case Study(cid:148) is introduced. Chapter 2 is intended to provide an over-
view of the radar probability of detection calculations and related topics.
Detection of fluctuating targets including Swerling I, II, III, and IV models is
presented and analyzed. Coherent and non-coherent integration are also intro-
duced. Cumulative probability of detection analysis is in this chapter. Visit 2 of
the design case study (cid:147)MyRadar(cid:148) is introduced.
Chapter 3 reviews radar waveforms, including CW, pulsed, and LFM. High
Range Resolution (HRR) waveforms and stepped frequency waveforms are
also analyzed. The concept of the Matched Filter (MF) is introduced and ana-
lyzed. Chapter 4 presents in detail the principles associated with the radar
ambiguity function. This includes the ambiguity function for single pulse, Lin-
ear Frequency Modulated pulses, train of unmodulated pulses, Barker codes,
and PRN codes. Pulse compression is introduced in Chapter 5. Both the MF
and the stretch processors are analyzed.
Chapter 6 contains treatment of the concepts of clutter. This includes both
surface and volume clutter. Chapter 7 presents clutter mitigation using Moving
Target Indicator (MTI). Delay line cancelers implementation to mitigate the
effects of clutter is analyzed.
Chapter 8 presents detailed analysis of Phased Arrays. Linear arrays are
investigated and detailed and MATLAB code is developed to calculate and plot
© 2004 by Chapman & Hall/CRC CRC Press LLC
the associated array patterns. Planar arrays, with various grid configurations,
are also presented.
Chapter 9 discusses target tracking radar systems. The first part of this chap-
ter covers the subject of single target tracking. Topics such as sequential lob-
ing, conical scan, monopulse, and range tracking are discussed in detail. The
second part of this chapter introduces multiple target tracking techniques.
Fixed gain tracking filters such as the αβ and the αβγ filters are presented in
detail. The concept of the Kalman filter is introduced. Special cases of the Kal-
man filter are analyzed in depth.
Chapter 10 is coauthored with Mr. J. Michael Madewell from the US Army
Space and Missile Defense Command, in Huntsville, Alabama. This chapter
presents an overview of Electronic Counter Measures (ECM) techniques. Top-
ics such as self screening and stand off jammers are presented. Radar chaff is
also analyzed and a chaff mitigation technique for Ballistic Missile Defense
(BMD) is introduced.
Chapter 11 is concerned with the Radar Cross Section (RCS). RCS depen-
dency on aspect angle, frequency, and polarization is discussed. The target
scattering matrix is developed. RCS formulas for many simple objects are pre-
sented. Complex object RCS is discussed, and target fluctuation models are
introduced. Chapter 12 is coauthored with Dr. Brian Smith from the US Army
Aviation and Missile Command (AMCOM), Redstone Arsenal in Alabama.
This chapter presents the topic of Tactical Synthetic Aperture Radar (SAR).
The topics of this chapter include: SAR signal processing, SAR design consid-
erations, and the SAR radar equation. Finally Chapter 13 presents an overview
of signal processing.
Using the material presented in this book and the MATLAB code designed
by the authors by any entity or person is strictly at will. The authors and the
publisher are neither liable nor responsible for any material or non-material
losses, loss of wages, personal or property damages of any kind, or for any
other type of damages of any and all types that may be incurred by using this
book.
Bassem R. Mahafza
Huntsville, Alabama
July, 2003
Atef Z. Elsherbeni
Oxford, Mississippi
July, 2003
© 2004 by Chapman & Hall/CRC CRC Press LLC
Acknowledgment

The authors first would like to thank God for giving us the endurance and
perseverance to complete this work. Many thanks are due to our families who
have given up and sacrificed many hours in order to allow us to complete this
book. The authors would like to also thank all of our colleagues and friends for
their support during the preparation of this book. Special thanks are due to
Brian Smith, James Michael Madewell, Patrick Barker, David Hall, Mohamed
Al-Sharkawy, and Matthew Inman who have coauthored and/or reviewed some
of the material in this reference book.
© 2004 by Chapman & Hall/CRC CRC Press LLC
Table of Contents
Preface
Acknowledgment

PART I
Chapter 1
Introduction to Radar Basics
1.1. Radar Classifications
1.2. Range
1.3. Range Resolution
1.4. Doppler Frequency
1.5. The Radar Equation
1.5.1. Radar Reference Range
1.6. Search (Surveillance)
1.6.1. Mini Design Case Study 1.1
1.7. Pulse Integration
1.7.1. Coherent Integration
1.7.2. Non-Coherent Integration
1.7.3. Detection Range with Pulse Integration
1.7.4. Mini Design Case Study 1.2
1.8. Radar Losses
1.8.1. Transmit and Receive Losses
1.8.2. Antenna Pattern Loss and Scan Loss
1.8.3. Atmospheric Loss
1.8.4. Collapsing Loss
1.8.5. Processing Losses
1.8.6. Other Losses
1.9. (cid:147)MyRadar(cid:148) Design Case Study - Visit 1
© 2004 by Chapman & Hall/CRC CRC Press LLC
1.9.1 Authors and Publisher Disclaimer
1.9.2. Problem Statement
1.9.3. A Design
1.9.4. A Design Alternative
1.10. MATLAB Program and Function Listings
Listing 1.1. Function (cid:147)radar_eq.m(cid:148)
Listing 1.2. Program (cid:147)fig1_12.m(cid:148)
Listing 1.3. Program (cid:147)fig1_13.m(cid:148)
Listing 1.4. Program (cid:147)ref_snr.m(cid:148)
Listing 1.5. Function (cid:147)power_aperture.m(cid:148)
Listing 1.6. Program (cid:147)fig1_16.m(cid:148)
Listing 1.7. Program (cid:147)casestudy1_1.m(cid:148)
Listing 1.8. Program (cid:147)fig1_19.m(cid:148)
Listing 1.9. Program (cid:147)fig1_21.m(cid:148)
Listing 1.10. Function (cid:147)pulse_integration.m(cid:148)
Listing 1.11. Program (cid:147)myradarvisit1_1.m(cid:148)
Listing 1.12. Program (cid:147)fig1_27.m(cid:148)
Appendix 1A
Pulsed Radar
1A.1. Introduction
1A.2. Range and Doppler Ambiguities
1A.3. Resolving Range Ambiguity
1A.4. Resolving Doppler Ambiguity
Appendix 1B
Noise Figure
Chapter 2
Radar Detection
2.1. Detection in the Presence of Noise
2.2. Probability of False Alarm
2.3. Probability of Detection
2.4. Pulse Integration
2.4.1. Coherent Integration
2.4.2. Non-Coherent Integration
2.4.3. Mini Design Case Study 2.1
2.5. Detection of Fluctuating Targets
2.5.1. Threshold Selection
© 2004 by Chapman & Hall/CRC CRC Press LLC
2.6. Probability of Detection Calculation
2.6.1. Detection of Swerling V Targets
2.6.2. Detection of Swerling I Targets
2.6.3. Detection of Swerling II Targets
2.6.4. Detection of Swerling III Targets
2.6.5. Detection of Swerling IV Targets
2.7. The Radar Equation Revisited
2.8. Cumulative Probability of Detection
2.8.1. Mini Design Case Study 2.2
2.9. Constant False Alarm Rate (CFAR)
2.9.1. Cell-Averaging CFAR (Single Pulse)
2.9.2. Cell-Averaging CFAR with Non-Coherent Integra-
tion
2.10. (cid:147)MyRadar(cid:148) Design Case Study - Visit 2
2.10.1. Problem Statement
2.10.2. A Design
2.10.2.1. Single Pulse (per Frame) Design Option
2.10.2.2. Non-Coherent Integration Design Option
2.11. MATLAB Program and Function Listings
Listing 2.1. Program (cid:147)fig2_2.m(cid:148)
Listing 2.2. Function (cid:147)que_func.m(cid:148)
Listing 2.3. Program (cid:147)fig2_3.m(cid:148)
Listing 2.4. Function (cid:147)marcumsq.m(cid:148)
Listing 2.5. Program (cid:147)prob_snr1.m(cid:148)
Listing 2.6. Program (cid:147)fig2_6a.m(cid:148)
Listing 2.7. Function (cid:147)improv_fac.m(cid:148)
Listing 2.8 Program (cid:147)fig2_6b.m(cid:148)
Listing 2.9. Function (cid:147)incomplete_gamma.m(cid:148)
Listing 2.10. Function (cid:147)factor.m(cid:148)
Listing 2.11. Program (cid:147)fig2_7.m(cid:148)
Listing 2.12. Function (cid:147)threshold.m(cid:148)
Listing 2.13. Program (cid:147)fig2_8.m(cid:148)
Listing 2.14. Function (cid:147)pd_swerling5.m(cid:148)
Listing 2.15. Program (cid:147)fig2_9.m(cid:148)
Listing 2.16. Function (cid:147)pd_swerling1.m(cid:148)
Listing 2.17. Program (cid:147)fig2_10.m(cid:148)
Listing 2.18. Program (cid:147)fig2_11ab.m(cid:148)
Listing 2.19. Function (cid:147)pd_swerling2.m(cid:148)
Listing 2.20. Program (cid:147)fig2_12.m(cid:148)
Listing 2.21. Function (cid:147)pd_swerling3.m(cid:148)
Listing 2.22. Program (cid:147)fig2_13.m(cid:148)
Listing 2.23 Function (cid:147)pd_swerling4.m(cid:148)
Listing 2.24. Program (cid:147)fig2_14.m(cid:148)
© 2004 by Chapman & Hall/CRC CRC Press LLC