Combat in the Mediterranean, especially during the Allied invasion of Sicily and the Italian mainland, was marked by significant air attacks by Italian and German aircraft. It was also marked by the relatively poor performance of anti-aircraft gunnery. To improve their performance, the Navy grew increasingly interested in a radar that was dedicated to the continual plotting of the location of aircraft at close range, when their relative position to the ship was changing rapidly. The idea was to fit all ships of the destroyer size and larger to allow the entire task force to operate effectively against aircraft. A formal requirement for this new "Target Indication", or "TI", role was released in December 1942.