During the 1990s there was a plan to locate a US Navy Relocatable Over The Horizon Radar, the AN/TPS-71 (ROTHR), in the United Kingdom. This was to provide cover to the North over the Norwegian Sea to detect Soviet ships and aircraft transiting from their bases in the Murmansk Oblast into the North Atlantic. In 1990, a Memorandum of Understanding (MoU) was signed between the British and US Governments to install the radar, initially for a two-year trial commencing in 1993.
