Arnold L. McConchie Jr., 74, formerly of Owls Head and Rockland, died peacefully Saturday, Jan. 27, 2018, at his home.

Mr. McConchie was born to Arnold L. and M. Lucille (Shute) McConchie Oct. 4, 1943, in Rockland. He attended Owls Head and Rockland schools and graduated from Rockland High School in 1961. During his youth, he spent many enjoyable summers living on and/or lobster fishing around Large Green Island out in Penobscot Bay.

Following his graduation from MIT in 1965, Mr. McConchie embarked on a career in radar design at The Raytheon Co., retiring from its Tucson, Ariz., facility in 2003. At Raytheon, he contributed many analyses and simulations relating to radar design choices. These ran the gamut from waveform design to interference mitigation techniques to radar measurement of the microdynamic motion of rolling reentry vehicles. As part of his work in waveform design and processing, he also became an expert in the theory, design and alignment of chirp (pulsed, linear-FM) radar.

In retirement, Mr. McConchie actively pursued his lifelong interest in genealogy, amassing thousands of names in his personal tree. Meeting and/or collaborating with several cousins who were also doing family history research made this pursuit doubly rewarding. Highlights of this genealogical research included tracing his family name back to his fifth great-grandparents in Scotland and uncovering direct descent from 12 DAR-recognized Revolutionary patriots.

Mr. McConchie was a member of the Arizona-Sonora Desert Museum and the New England Historic Genealogical Society and a former member of the Clan Donnachaidh Society.

In lieu of flowers, make a donation to a charity of your choice, in memory of Arnold.

Local arrangements are with Burpee, Carpenter & Hutchins Funeral Home, Rockland.