Page "Military history of the United Kingdom during World War II" Paragraph 199

Other important advances occurred in the technical field.

The first navigation aid, GEE, was introduced to help pilots to find their targets.

Window, small metal strips dropped from aircraft, was introduced to help confuse the German radars.

Planes also got their own radar, the H2S radar system.

It provided a radar map of the ground beneath the aircraft, allowing navigation with more accuracy to cities like Berlin which were at that time beyond the effective range of systems like Gee.

However, probably the most important innovation to improve targeting accuracy was tactical, not technical.

It was the introduction of the pathfinder system.

Pathfinders were groups of specially trained aircrews who flew ahead of the main raid and marked the target.

Their use greatly improved the accuracy and destructiveness of raids.