What where the preparations before D-day?

Answer 1

First, the navy gained control of the sea lanes so that troops and supplies could move without threat of the Nazi U-Boats. Then, the Air Forces isolated he Western Part of France so that Nazi reinforcements and supplies, particularly tank units, could not reach the isolated garrisons guarding the coasts. Next, the Intelligence Services created an elaborate ruse involving a nonexistent army, led by Patton, scheduled to attack the Pas De Calais, the spot where Hitler predicted the allies would land, complete with phony radio traffic and movie prop tanks, artillery, and barracks. Meanwhile, the British and American field forces underwent intensive training in amphibious and airborne operations, eventually conducting exercises on sections of Britsh beaches that were chosen because of their resemblance to those in Normandy assigned to each particular unit. Eisenhower also needed the right combination of moon and tide. May proved premature; so the joint command settled on June 5th. In the event, rain postponed the invasion to Tuesday, June 6th, 1944.