Vernon Ellsworth Derr, a pioneer and leader in optical remote sensing of the atmosphere, died on 24 July 2003 in Boulder, Colorado, of complications of Parkinson’s disease.
Born on 21 November 1921 in Baltimore, Maryland, Vernon served in the US Army Signal Corps with the rank of captain. He then entered St. John’s College in Annapolis, Maryland, and graduated with an AB in 1948. He was awarded a PhD in physics by Johns Hopkins University in 1959. His thesis work, conducted under the guidance of Richard Cox, was on the irreversibility of quantum mechanical systems perturbed by random forces; it led to a Physics Review paper in 1960.
Vernon then joined the Martin Co in Orlando, Florida, as principal scientist in charge of the quantum electronics group, which used wavelengths spanning the range from millimeter waves to UV to study molecular structures. For spectroscopic studies, the group developed instruments, including lasers, masers, and a millimeter-wave molecular beam machine, for applications such as nuclear pumping of lasers and atomic frequency standards.
In 1967, Vernon joined the newly formed Wave Propagation Laboratory of the Environmental Science Services Administration (now the National Oceanic and Atmospheric Administration, NOAA). This remote-sensing laboratory, a descendant of the Central Radio Propagation Laboratory of the National Bureau of Standards, already had expertise at radio frequencies ranging up to 100 GHz. The inclusion of Vernon (and three other members of his Martin team) added critically needed competence in millimeter, IR, and optical frequencies. As head of the submillimeter section, Vernon pioneered the development of an extraordinarily wide range of active (radarlike), passive (radio-metric), and line-of-sight (attenuation) studies of the atmosphere and its constituents.
During the early 1970s, his research group developed one of the first transportable light detection and ranging systems for the study of air pollution. The scannable LIDAR system transmitted IR, visible, or UV radiation, which enabled multi-wavelength studies of the scattering and transmission characteristics of atmospheric aerosols. That system was deployed in several experiments, including some of the earliest studies of air pollution—the Denver Brown Cloud—in the Denver, Colorado, basin. In keeping with Vernon’s insatiable scientific curiosity and broad range of interests, he also used LIDAR to study ice characteristics in cirrus clouds and to investigate the feasibility of Raman LIDAR measurements of profiles of temperature and water vapor.
Working with Ron Schwiesow of the submillimeter section, Vernon also developed one of the earliest carbon dioxide Doppler LIDAR systems to measure atmospheric winds. Mounted initially in a small camper and later deployed in a light aircraft, the continuous-wave instrument obtained some of the earliest measurements of airflow in desert dust devils and waterspouts. That research set the stage for many later applications of Doppler LIDAR to study a wide variety of atmospheric phenomena, including canyon and valley flows, sea breezes, low-level jets, wake vortices, thunderstorm outflows, and forest fires.
A unique contribution was Vernon’s organization and editing of the 30-chapter, 650-page text Remote Sensing of the Troposphere (NOAA, 1972). The book is a landmark overview of the physics of the lower atmosphere and the application of remote-sensing techniques to atmospheric problems.
In 1981, George Ludwig selected Vernon as deputy director of the Environmental Research Laboratories, the 1300-person, 10-laboratory research arm of NOAA. From 1983 to 1988, he served as director of NOAA-ERL and then, until his retirement in 1991, as senior scientist in NOAA’s Office of Oceanic and Atmospheric Research. From 1991 to 1994, he was a senior scientist in the jointly sponsored NOAA-University of Colorado Cooperative Institute for Research in Environmental Science at CU Boulder.
Vernon was an excellent scientist and science administrator. A stimulating communicator, teacher, and mentor, he taught an optical remote-sensing course at Colorado for many years as an adjunct professor. His awards included a US Presidential Distinguished Rank Award in 1988 and the Department of Commerce’s highest award, the Gold Medal, in 1991.
Until afflicted with Parkinson’s disease, Vernon enjoyed sports, especially tennis. He was active in music circles and sang in community choruses, including Gilbert and Sullivan operettas. Vernon was blessed with 60 years of happy marriage and a close family of two daughters, a son, and a grandson.