Hall - Principles of Naval Weapons Systems 4AH, ksiazki EN, Ship
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Principles of
Naval Weapons Systems
Edited by CDR Joseph Hall, USN
Introduction
In the early twentieth century, the instruments of war were simply called weapons.
The cannon, the rifle, or the bayonet were all considered separate pieces of weaponry to
be used in combat. By the Second World War, technology began to be integrated into
combat. The invention of radar and sonar extended the field of combat to greater and
greater ranges, and it was no longer necessary to sight targets directly. As technology
progressed, the very nature of weapons also changed. Now, it is no longer sufficient to
discuss individual pieces of weaponry, they must be taken in the context of the entire
weapons system
, which is the complete set of interrelating pieces that function together to
achieve the goal of destroying a target.
The complete description of a weapons system must include all of the means of
exchanging information between sub-systems, called
communication
systems; all means
used to locate the target, called
sensors
; all means used to store, launch and deliver the
weapon to the target, called
delivery
sub-systems; and all means used to inflict damage
upon the target, called
destruction
sub-systems.
In this book, we will discuss how the various sub-systems function. The goal is to
understand the
principles of operation
of many different weapons systems. It is expected
that the reader will supplement this material with one of the many fine books describing
the arsenal of weapons currently in use by the major militaries of the world.
To understand how a complicated device such as a weapons system works, it is
often helpful to perform some level of abstraction first. In some ways, this is also how
weapons systems are designed. The abstraction is simply to ask “what are the inputs and
outputs?” This question can be applied at many different levels. To illustrate this concept,
consider the overall weapons system. The inputs come from the target and/or an operator.
The output is the destructive force that damages the target.
At the next level of abstraction, the roles of the major sub-sections can be
prescribed. The sensor sub-section takes the signals from the target and outputs the
location and direction of movement of the target to the delivery system. The delivery
system’s output is to put the weapon in close proximity to the target. Finally, given some
small separation from the weapon to the target, the destructive system outputs the
destructive force to the target. Of course, most of this is obvious. However, when this
method of breaking systems down into smaller functional sub-systems is applied to smaller
and smaller parts, it turns out to be a very useful way to understand how complicated
systems work. Once the roles of the various sub-systems are understood, then the details
of its operation can be put into context. This is the approach taken here.
i
Table of Contents
Chapter 1 _____________________________________________________________11
The Parameters of a Wave ___________________________________________________ 11
Traveling Waves ___________________________________________________________ 16
Frequency vs. Time Domain _________________________________________________ 17
Chapter 2 _____________________________________________________________21
Basic Phenomena ___________________________________________________________ 21
Reflection ______________________________________________________________________23
Refraction ______________________________________________________________________24
Interference _____________________________________________________________________25
Diffraction______________________________________________________________________26
Antennas _________________________________________________________________ 27
The Dipole Antenna ______________________________________________________________27
Polarization _____________________________________________________________________28
Antenna Beam-forming ___________________________________________________________30
Modes of Propagation in Air _________________________________________________ 32
The Electromagnetic Spectrum _____________________________________________________32
Ground Waves __________________________________________________________________32
Sky Waves______________________________________________________________________33
Line of Sight ____________________________________________________________________36
Chapter 3 _____________________________________________________________39
Basic Components __________________________________________________________ 39
Transmitter _____________________________________________________________________40
The Transmission Channel_________________________________________________________40
The Receiver ____________________________________________________________________41
Modulation________________________________________________________________ 41
Noise _____________________________________________________________________ 42
Broadband (White) Noise __________________________________________________________42
Narrowband (Interference) Noise ____________________________________________________42
Chapter 4 _____________________________________________________________45
Amplitude Modulation (AM) _________________________________________________ 46
An AM system _____________________________________________________________ 48
The AM Spectrum__________________________________________________________ 49
Bandwidth______________________________________________________________________49
Efficiency ______________________________________________________________________51
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Frequency Modulation (FM) _________________________________________________ 54
Bandwidth of FM __________________________________________________________ 55
Immunity to Static__________________________________________________________ 56
Phase Modulation (PM) _____________________________________________________ 56
Single Side-band (SSB) ______________________________________________________ 57
Chapter 5 _____________________________________________________________61
The Binary Representation___________________________________________________ 62
The Binary number system _________________________________________________________62
Bits, bytes and words _____________________________________________________________64
Basic Components __________________________________________________________ 64
Central Processing Unit (CPU)______________________________________________________65
Bus ___________________________________________________________________________68
Memory ________________________________________________________________________69
Input and Output (I/O) ____________________________________________________________71
Chapter 6 _____________________________________________________________73
Digital Data with Analog Signals ______________________________________________ 74
Amplitude Shift-Keying (ASK) _____________________________________________________74
Frequency Shift-Keying (FSK) ______________________________________________________75
Phase Shift-Keying (PSK) _________________________________________________________75
M-ary Frequency/Phase Keying _____________________________________________________75
Amplitude-Phase Keying __________________________________________________________76
Capacity _______________________________________________________________________76
Minimum Shift Keying (MSK) _____________________________________________________77
Analog Data with Digital Signals ______________________________________________ 77
Sampling _______________________________________________________________________78
Encoding _______________________________________________________________________78
Digital - Digital ____________________________________________________________ 79
Parity Checksum _________________________________________________________________80
Chapter 7 _____________________________________________________________81
Multiplexing _______________________________________________________________ 81
Frequency Domain Multiplexing ____________________________________________________81
Time Domain Multiplexing ________________________________________________________82
Spread Spectrum Multiplexing______________________________________________________82
Local Area Networks (LAN) _________________________________________________ 83
Topology _______________________________________________________________________83
Protocols _______________________________________________________________________84
Wide Area Networks (WANs) ________________________________________________ 84
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Fixed Wide Area Networks_________________________________________________________84
Cellular Networks ________________________________________________________________85
Satellite Networks ________________________________________________________________85
Chapter 8 _____________________________________________________________87
Principles of Operation ______________________________________________________ 87
Mechanization _____________________________________________________________ 89
Radar performance _________________________________________________________ 95
Pulse Width_____________________________________________________________________95
Pulse Repetition Frequency (PRF) ___________________________________________________97
Radar Frequency _________________________________________________________________98
Theoretical Maximum Range Equation _________________________________________ 99
Chapter 9 ____________________________________________________________101
Principle of Operation______________________________________________________ 101
Frequency Modulated Continuous Wave (FMCW) radar _________________________ 104
Chapter 10 ___________________________________________________________109
Radial Velocity Discrimination_______________________________________________ 109
Differentiation__________________________________________________________________109
Moving Target Indicator (MTI) ____________________________________________________110
Pulse Doppler Radar _____________________________________________________________112
Limitations ____________________________________________________________________113
High Resolution Radar _____________________________________________________ 115
Pulse Compression ______________________________________________________________115
Synthetic Aperture Radar (SAR) ___________________________________________________116
Inverse Synthetic Aperture Radar (ISAR) ____________________________________________118
Phased Array Radar _______________________________________________________ 119
Chapter 11 ___________________________________________________________123
Radar Servo Tracking System _______________________________________________ 123
Range Tracking ___________________________________________________________ 128
Track-While-Scan (TWS)___________________________________________________ 129
Phased-Array Tracking ____________________________________________________ 132
Tracking Networks ________________________________________________________ 133
Chapter 12 ___________________________________________________________135
The Electromagnetic Spectrum ______________________________________________ 135
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