Also called the ROC.
A defence warning organisation operating in the United Kingdom between 1925 and 1995. It was created to provide a system for detecting, tracking and reporting aircraft over Britain. In 1955 the detection and reporting of nuclear blasts and fall-out was introduced. By 1965 the aircraft role was no longer needed and the corps formed the field force for the United Kingdom Warning and Monitoring Organisation (UKWMO).
A unique type of an ROC underground monitoring post built at Great Witchingham during the Cold War. (© NCC)