Tutorial 5.2
Pulse Compression in Radar Systems

Dr. Marvin Cohen - Georgia Tech Research Institute

Thu, 29 April 2004, 1:30 PM - 5:30 PM

Abstract

In the introduction, the principles, motivations, and terminology related to radar pulse compression are presented and discussed. The general concepts of range resolution, range sidelobes, and processing losses are developed. The lecture continues with an in-depth discussion of specific pulse compression techniques.

Frequency coding techniques including linear frequency modulation, non-linear frequency modulation, Stretch, and stepped frequency modulation are presented. Biphase codes such as Barker, Combined Barker, pseudorandom, minimum peak sidelobe, and Golay codes are explained and illustrated. Polyphase codes such as Welti, Frank, and P4 codes are exhibited and discussed as well. Hybrid phase and frequency codes are introduced.

Mismatch filtering for range sidelobe suppression is presented - both the classical weighting functions for linear frequency modulated waveforms, as well as various lesser-known weighting functions for phase-coded waveforms. The tradeoffs between resolution, signal-to-noise ratio, and range sidelobe levels are quantified.

The Doppler response of the various pulse compression techniques is explored via analysis of the radar ambiguity diagram. Frequency-modulated and phase-modulated waveforms of comparable bandwidth and pulsewidth are compared as to their Doppler response.

The lecture concludes with a summary comparison of simple-pulse, frequency-modulated, and phase-modulated radar waveforms and their potential applications. An extensive bibliography is included.

Bio

Dr. Cohen received his Ph. D. in theoretical mathematics from the University of Miami in 1978. He is a Principle Research Scientist and Fellow of GTRI and a Fellow of the IEEE. He is also CEO of IRTA, Inc. and Sole Proprietor of MCA, currently supporting industry, AFRL, and NAVAIR in advanced technology programs. Dr. Cohen is co-author of Radar Design principles, 2nd Edition, has authored over 120 professional publications, and teaches in advance technology short courses. In 1978 he joined the staff of Norden Systems and there developed the pulse compression codes and filters for the Assault Breaker radar, the precursor of the JSTARS radar. Dr. Cohen joined the professional staff of the Georgia Tech Research Institute in 1981, at which time he began work on the development of radar techniques and algorithms for the identification of moving and.stationary ground targets. This work culminated in publication in the late 80s of the first descriptions of phenomenology and algorithms that have since been incorporated in operational platforms. Starting in the late 1980s, Dr. Cohen began to focus on identification fusion. Throughout his career, he has pursued his interest in radar pulse compression codes and filters by continuing to develop techniques and results, teach, and review the evolving research in this fascinating area.