Radar, barrage balloons and anti-aircraft guns

• Radar had been developed which could detect aircraft, so they were able to concentrate the defence just where it was needed
• • Barrage balloons were placed in the skies above London to try and stop the German bombers from coming in too low - this reduced the level of success of the bombing campaigns.
• • Anti-aircraft guns were also built to try to limit the potential damage that German bombers could cause.