Royal Observer Corps
The Royal Observer Corps (ROC) was a civil defence organisation intended for the visual detection, identification, tracking and reporting of aircraft over Great Britain. It operated in the United Kingdom between 29 October 1925 and 31 December 1995, when the Corps' civilian volunteers were stood down. (ROC headquarters staff at RAF Bentley Priory stood down on 31 March 1996). Composed mainly of civilian spare-time volunteers, ROC personnel wore a Royal Air Force (RAF) style uniform and latterly came under the administrative control of RAF Strike Command and the operational control of the Home Office. Civilian volunteers were trained and administered by a small cadre of professional full-time officers under the command of the Commandant Royal Observer Corps; latterly a serving RAF Air Commodore.
Ground Observer Corps
The first Ground Observer Corps was a World War II Civil Defense program of the United States Army Air Forces to protect United States territory against air attack. The 1.5 million civilian observers at 14,000 coastal observation posts performed naked eye and binocular searches to detect German or Japanese aircraft. Observations were telephoned to filter centers, which in turn forwarded authenticated reports to the Aircraft Warning Service, which also received reports from Army radar stations. The program ended in 1944. A few Aircraft Warning Service Observation Towers survive as relics.