A History of the CHILL Radar’s Technical Evolution

Cut and paste from Word (shared doc as of 6 Aug 2020):

National Science Foundation (NSF) base funding for the CSU-CHILL radar ended in the early months of 2019. . This marked the end of a 47-year period of research data collection that began in 1972 during the National Hail Research Experiment (NHRE). . This historical summary is focused on the technical evolution of the CHILL radar that allowed it to remain active for such a long lifetime.

The radar’s lifetime has been broken into three phases: (1) The system’s original development and active deployment period (1972 – 1982). . (2) The period of significant technical upgrades made possible by initiation of NSF base funding support while the radar continued to be hosted at Champaign, Illinois by the Illinois State Water Survey (ISWS), 1984 – 1990). (3) The transfer of the radar to Colorado State University (July 1990 – May 2019).

The series of NSF cooperative agreements that maintained base funding for the radar included a requirement for a facility manager position. . In April 1988, the author assumed this position from John Vogel at the Illinois State Water Survey. Employment in this capacity continued through February 2019. . This allowed direct involvement with much of time period 2 and essentially all of period 3. . Most references for period 1 were obtained from boxes of archived files received from Gene Mueller, the Electrical Engineer primarily responsible for the radar’s original development. . Historical material pertaining to the NHRE project was kindly supplied by Laura Hoff of the NCAR archives department. . Nancy Wescott and Steve Hilberg took the time to extract a series of useful photographs from the ISWS archives. . Dave Brunkow, who served as an electrical engineer with the CHILL radar during all three portions of the radar’s lifetime, also served as the primary reviewer of this document. . The author is solely responsible for the selection of the elements included in this summary as well as any errors or omissions.