Hulburt was born in
Vermillion, South Dakota, on 12 October 1890. He was educated at
Johns Hopkins University, where his father was a professor of mathematics. He worked for 31 years at the
United States Naval Research Laboratory, serving as head of the Physical Optics Division from 1929 to 1949, and Director of Research from 1949 to 1955. In 1926, he and
Albert H. Taylor worked out several basic characteristics of the
ionosphere, including the distribution of its electron density and dependence on solar elevation, by studying the propagation of radio signals in the atmosphere. They collaborated with
Gregory Breit and
Merle Tuve in the development of the
ionosonde device used to study the ionosphere. Hulburt also studied how
solar X-rays and extreme ultraviolet radiation were responsible for ionization in
E- and
F-regions of the upper atmosphere, with the use of
V-2 rockets captured from Germany at the end of
World War II to make high-altitude observations. During
World War II, he advised the
United States Navy on camouflage designs for its ships. His honors and awards included the
Frederic Ives Medal of the
Optical Society of America (1955), the
John Adam Fleming Medal of the
American Geophysical Union (1964), and the degree of
Doctor of Humane Letters from Johns Hopkins University (1980). Hulburt died in
Easton, Maryland, on 11 October 1982. == Selected publications ==