The allies' most advanced technologies were showcased by the anti-aircraft defence against the German V-1 cruise missiles (V stands for Vergeltungswaffe, "retaliation weapon"). The 419th and 601st Antiaircraft Gun Battalions of the US Army were first allocated to the Folkestone-Dover coast to defend London, and then moved to <answer>Belgium</answer> to become part of the "Antwerp X" project. With the liberation of Antwerp, the port city immediately became the highest priority target, and received the largest number of V-1 and V-2 missiles of any city. The smallest tactical unit of the operation was a gun battery consisting of four 90 mm guns firing shells equipped with a radio proximity fuse. Incoming targets were acquired and automatically tracked by SCR-584 radar, developed at the MIT Rad Lab. Output from the gun-laying radar was fed to the M-9 director, an electronic analog computer developed at Bell Laboratories to calculate the lead and elevation corrections for the guns. With the help of these three technologies, close to 90% of the V-1 missiles, on track to the defence zone around the port, were destroyed.
Where did the US Army 419th and 601st relocate to as part of the Antwerp X project?
Belgium