Operation 'Corona' was a RAF

Royal Air Force

The Royal Air Force is the aerial warfare service branch of the British Armed Forces. Formed on 1 April 1918, it is the oldest independent air force in the world...

 initiative to confuse German

Germany

Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

 night fighter

Night fighter

A night fighter is a fighter aircraft adapted for use at night or in other times of bad visibility...

s during RAF bomber raids on German cities during WWII

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

. Native German speakers impersonated German Air Defence officers. They initiated communications via radio with German nightfighter pilots and countermanded previously given orders, thus reducing the efficiency of German air defence.

The operation was first launched during the attack on the German industrial center of Kassel

Kassel

Kassel is a town located on the Fulda River in northern Hesse, Germany. It is the administrative seat of the Kassel Regierungsbezirk and the Kreis of the same name and has approximately 195,000 inhabitants.- History :...

 on the night of 22 October to 23 October 1943 in which 90% of the city was burned, leaving 10,000 dead and 150,000 homeless.

Operation 'Corona' was made possible by the Jewish diaspora when many people, mostly Jews, fled Nazi

Nazism

Nazism, the common short form name of National Socialism was the ideology and practice of the Nazi Party and of Nazi Germany...

-Germany to England. These people were very valuable to RAF Bomber Command

RAF Bomber Command

RAF Bomber Command controlled the RAF's bomber forces from 1936 to 1968. During World War II the command destroyed a significant proportion of Nazi Germany's industries and many German cities, and in the 1960s stood at the peak of its postwar military power with the V bombers and a supplemental...

, since between them they natively spoke any German

Germany

Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

 accent and hence were capable of countermanding the orders given from the senior officers in the Air Defence headquarters, and so could redirect the nightfighters to other targets or give them orders to land immediately at an airbase.

When confronted with Corona personnel countermanding genuine German orders the Luftwaffe responded by replacing male fighter controllers with female ones. The British counter-moved by then using Women's Auxiliary Air Force

Women's Auxiliary Air Force

The Women's Auxiliary Air Force , whose members were invariably referred to as Waafs , was the female auxiliary of the Royal Air Force during World War II, established in 1939. At its peak strength, in 1943, WAAF numbers exceeded 180,000, with over 2,000 women enlisting per week.A Women's Royal Air...

personnel.