Tutorial 2.1
Radar Detection Theory

Dr. Harry Urkowitz - Lockheed Martin, MS2, Dr. Thomas F Halpin - Lockheed Martin MS2

Wed, 28 April 2004, 6:00 PM - 10:00 PM

Abstract

At its base, radar detection theory is an application of a statistical test of two hypotheses: 1) Noise (and clutter) present; 2) Noise plus signal present. The Neyman Pearson test is appropriate here. In such a test, there are two types of error may occur: 1) Noise alone may be present, but signal may be declared (false alarm); 2) Signal may be present, but not detected (false dismissal). The probability of false alarm is held fixed at an acceptable values and the probability of correct detection is maximized. The appropriate quantity to be obtained is the likelihood ratio. The radar receiver obtains an equivalent to the likelihood ratio, by means of matched filtering, followed by envelope or squared envelope extraction. The resulting sequence of envelopes may undergo further processing.

The radar detection framework is a combination of so-called coherent processing and pulse to pulse noncoherent processing. Coherent processing involves exploiting the phase characteristics of as radar echo by means of matched filtering that exploits not only the phase characteristic of each radar pulse by means of ?matched filtering?, but also the pulse to pulse phase variation arising from Doppler shift caused by target closing speed. The pulse to pulse coherent processing, if multiple pulses are received, involves a bank of Doppler filters followed by envelope detectors, and, often, further noncoherent sample to sample (or pulse to pulse) integration, i.e., addition of envelopes or squared envelopes. The results of such processing depend the pulse to pulse target fluctuation. The detection characteristics of various pulse to pulse fluctuation of models, including the Swerling models, will be explained. Various forms of constant false alarm rate (CFAR) will be explained, including so-called distribution free CFAR.

Bios

Harry Urkowitz (LF) received the BSEE degree from Drexel University and the MSSE and PhD degrees from the University of Pennsylvania. He is in the Radar System Engineering Activity of Lockheed Martin in Moorestown, NJ and has served on many IEEE boards and committees. In 2000 he received an IEEE Third Millennium Medal and was elected a Fellow of the Military Sensing Symposia. For nearly 40 years Dr. Urkowitz was an Adjunct Professor of Electrical and Computer Engineering at Drexel University Graduate School. He is the author of the book: Signal Theory and Random Processes, published by Artech House in 1983. Dr. Urkowitz holds twelve patents and has more than 80 published papers.

Dr. Thomas F Halpin - Lockheed Martin MS2

Tom Halpin is a Lead Member of the Engineering Staff at Lockheed Martin Maritime Sensors & Systems (MS2) in Moorestown, NJ. He joined this facility in 1984 and has been involved with the design, analysis and integration of various land and shipboard radar systems. He is a former Chairman of the IEEE Philadelphia Chapter of AES. He has authored numerous technical publications. He holds BS, MS and PhD Degrees in Electrical Engineering from Drexel University, and is currently an Adjunct Professor in the Electrical and Computer Engineer Department at Drexel.