Obituary

Dwight O. North


Among the recipients of the IT Society's Golden Jubilee

Awards for Technological Innovation was Dwight O. North,

who was cited for his invention of the matched filter.

Sadly, Dr. North died on June 26, 1998, just two

months before the awards were presented at ISIT'98 at

MIT. On September 8, former IT Society Presidents Vince

Poor and Sergio Verd\'u presented the award to Dr. North's

wife, Evelyn, at her home in Princeton, New Jersey.

 

Of course, the importance of the matched filter concept

in communications and signal processing hardly needs to

be repeated here. Dr. North was the first to formalize

this concept, which he published in a 1943 classified

report at RCA Labs in Princeton. (North did not use the name

``matched filter''. This term was coined by David Middleton and

J.H. Van Vleck, who independently published the result

a year after North in a classified Harvard Radio Research

Lab report.) North's report was later reprinted in the

{\it Proceedings of the IEEE}, in July 1963. This remarkable

report introduced not only the matched filter, but also the

Rice distribution, the concept of false alarms to set a detection

threshold, studies of pre-detection and post-detection

integration, among other topics. Its anticipation of so many

of the issues that occupied the attention of radar engineers for

many years is quite remarkable.

 

Dwight North, or Don (for his initials - D.O.N.) as he was

known to his friends and colleagues, was born in Hartford,

Connecticut, and was educated at Wesleyan University and

at Caltech, from which he received a Ph.D. in Physics in

1933. From 1934 until his retirement in 1974, he worked

for RCA, first in Harrison, New Jersey, and then as an original

member of the technical staff at RCA's Princeton labs when

they were established in 1942. His interest in noise problems

began during the 1930's when he worked on the study of noise

in vacuum tubes operating in the 100MHz band, work being conducted

at RCA during its development of commercial television.

(His interest in noise problems even extended to the naming

of the street on which he was a longtime resident in Princeton:

Random Road - so named because many of its original residents

were RCA "noise" experts, including Dwight North.) During

World War II, he worked at the MIT Radiation Lab on the

development of radar. After the war, he turned to the study

of solid state physics, which occupied most of the remainder

of his career at RCA.

 

According to Evelyn North, Dr. North was typically uninterested

in organizational recognitions of his work. However, when he

was informed of the Golden Jubilee award in a letter from Society

President Thomas Ericsson, he was reportedly very pleased

to be recognized in this way. Although Dwight North did not labor

long in our field, in inventing the matched filter he left a legacy

that will undoubtedly last into the very distant future.