Hermann Goering assured Hitler that his air force could defeat Britain without help, & that there was no need to invade.  The raids throughout the summer and fall of 1940 became known as the Battle of Britain.  The British Royal Air Force defended the island against huge odds.  This was in many real ways their finest hour.  Besides the dedicated air crews, the British had a technological edge.  Their new ____________ system allowed them to intercept the Germans without wasted time or fuel.  ​