During the WW2 RAF night bombing campaign over Europe, technology was created to detect and counter attack aircraft in the dark. With these developments came interesting advancements in electronic warfare and night fighting.

This video covers the creation of the Monica radar by the RAF and the German use of Flensburg radar to counter it. The capture of an intact Junkers 88 G1 provided useful intelligence that saved many Allied air crews.

For more information on the topic:
http://aircrewremembered.com/captured...

Interesting video from 1944 on how Monica worked:
   • TRE RSRE MALVERN MONICA  RADAR SY...