Peter Swerling, a 20th-century Renaissance man who made enormous contributions to the field of radar, died of cancer on 25 August at his home in Santa Monica, California.
Born in New York City on 4 March 1929, Swerling spent his formative years as a precocious youth in the magical world of the movies. His father, Jo Swerling, was one of the most successful screenwriters of the era.
When Swerling was 10 years old, his father, recognizing the analytical gifts of his son, granted Swerling his birthday request to meet Albert Einstein. The awed youngster spent an hour alone with the professor and then the professor visited with the family for the day, because, apparently, even Einstein was fascinated by the gossip of Hollywood. He advised the boy to pursue his studies in mathematics; however, his parting words were to not forget the important things--like baseball!
Swerling entered Caltech at age 15, graduating three years later in 1947 with an undergraduate degree in mathematics. After graduating Phi Beta Kappa with an AB in economics from Cornell University in 1949, he received his PhD in mathematics from UCLA in 1955. While in graduate school, he was employed full-time by Douglas Aircraft, not on the assembly line for which he had applied, but as a member of the staff of the newly formed Project RAND, an assignment that was the start of a remarkable career.
Best known for his work in radar during the heady days of the RAND Corp, Swerling was also a professor at the University of Southern California and a founder and president of Technology Service Corp. He served on the board of directors for a number of companies, and was a founder and long-term trustee of the Crossroads School, one of the most prominent K12 private schools in Los Angeles. He also carried out Einstein's advice: Swerling enjoyed hang gliding and bodysurfing, much to the concern of friends and family. He loved opera, particularly Wagnerian opera, and Shakespeare, which he apparently had memorized, being only mildly upset when the Bard was misquoted at various technical meetings.
Swerling is perhaps best known professionally for the class of statistically "fluctuating target" scattering models he developed in the early 1950s to characterize the performance of pulsed radar systems. He extended Jess Marcum's work on statistical detection of steady targets in noise to include the important effect of statistical fluctuations of the target itself. Swerling's target models became an essential tool in the design of practical radar systems. The work was recognized immediately by the radar community, and the models, which have endured, are referred to as Swerling Target I, II, III, and IV in the literature of radar. Less well known (intentionally so, for reasons of national security) is the profound influence of more sophisticated target models Swerling more recently developed for application to targets using stealth technology. This work first became publicly known during the Persian Gulf War.
Swerling's work in the area of least-squares estimation and recursive signal processing was the precursor to Kalman filtering, a now ubiquitous signal-processing procedure used in the estimation and control of dynamic systems. Before Richard Kalman's work, Swerling published papers in 1958 and 1959 on "stagewise" smoothing, which were the first efforts to set up and exploit the computational advantages of structuring least-squares estimation problems in a recursive setting.
Through his influence on former students and colleagues and his numerous publications, Swerling leaves enduring professional contributions achieved by few. He is sorely missed by all who knew him.
Harold P. Smith Jr
University of California, Berkeley
Raytheon Electronic Systems
El Segundo, California