Fundamentals of Electronic Warfare. . - Professional Reader - book review

Military Intelligence Professional Bulletin, Jan-March, 2003 by Richard A. Poisel

Fundamentals of Electronic warfare,

S. A. Vakin, L. N. Shustov, and R. H. Dunwell (Norwood, MA: Artech House, 2001)

Fundamentals of Electronic Warfare (EW) introduces the reader to the basic concepts involved in aircraft survivability equipment (ASE), with particular emphasis on defeating antiaircraft (AA) radars. The authors define EW as:

A set of measures and actions performed by the conflicting sides to detect and electronically attack enemy electronic systems for the control of forces and weapons, including high-precision weapons, as well as to electronically defend one's own electronic systems and other targets from technical intelligence (electronic intelligence, ELINT), lamming and nondeliberate interference.

The authors consider all methods of protecting aircraft part of the taxonomy of EW, to include regular jamming of air defense radars (called masking jamming), deception, jamming the radars on high-speed anti-radiation missiles (HARMs), and directed energy destruction of radars. All of these are referred to as types of jamming. Jamming is presented as a method of reducing the target's information stability. Information stability is the opposite of in formation damage, which is what a jam mer attempts to do to a targeted system.

With few exceptions, the material in this book (in particular Chapters 1 through 3) can be applied to all electronic attack (EA) analyses. These chapters present mathematical models of radar and jamming signals as well as models of systems as targets and jamming systems. These models are used in later chapters to analyze the effectiveness of various EW techniques.

Chapter 1 sets the stage for the material to follow. Basic terms are introduced and the problems associated with jamming AA thrusts are presented. This chapter develops mathematical models of the radar and HARM targets.

Chapter 2 presents mathematical models of jamming signals and systems. Application of zero-sum game theory is discussed at the end of Chapter 2 as an interesting way to view the radar and radar jamming situation.

Chapter 3 introduces four jamming effectiveness criteria. The first is based on the amount of information damage a jammer can achieve, and is developed using the tenants of information theory introduced by Shannon in 1948. The second criterion is based on "energy" which refers to the required jam-to-signal-power-ratio (JSR) needed at the radar to be effective. The last two effectiveness indicators of jamming are of particular interest to practitioners of the jamming art. One indicator is based on how usable it is in an operational and tactical environment; the other is based on the military utility considering economic constraints. All but the last one of these indicators have quantitative criteria developed in this chapter.

Chapter 4 introduces the jamming equation and its characteristics. This equation governs the entire jamming process and is used to ascertain the effectiveness of jammers against radars. Discussed are the various aspects of the parameters involved with this equation to include the effects of signal polarization and possible mismatches thereof, the attenuation of signals as they traverse space, and the aircraft radar cross section (RCS). Included are presentations on jamming coherent and noncoherent radars, synthetic aperture radars (SAR), and bistatic radars, as well as using jammers for screening.

Chapter 5 introduces the notions of passive and active-passive jamming. Passive jamming is another appellation for chaff while active-passive refers to combining aircraft survivability equipment (ASE) jamming with chaff by, for example, reflecting the ASE jamming signal off chaff, thereby misdirecting a jamming antiradiation missile (ARM).

The effectiveness of decoys and other forms of false targets is analyzed in Chapter 6. Techniques are presented that increase the RCS of decoys, such as corner reflector for radar signals. Characteristics of expendable thermal decoys, and their effectiveness, are presented for addressing the threat posed by heat-seeking ARMs.

The main point of the last chapter is that radar detection range decreases slowly with reduction in the RCS by physical means. Due to aerodynamic considerations, it is not possible to reduce the physical RCS past a certain point where modern AA radars can still be effective. However, if the reflection characteristics of the aircraft or the atmospheric parameters between the radar and the aircraft can be changed, detection range decreases faster. This is important, for example, for reduction in the power and size of an ASE jammer as well as expenditure rates for passive and active-passive devices. The technologies discussed for accomplishing this include radio frequency absorptive coatings for the aircraft surface and surface design so that reflected radar signals interfere with one another to cancel and reduce the RCS of antennas on the aircraft. Also discussed are the effects of changing the atmosphere between the radar and aircraft by artificial ionization and nuclear means.