Monica tail warning radar
Encyclopedia
Monica was a range-only tail warning radar
for bombers, introduced by the RAF
in the spring of 1942. Officially known as ARI 5664, it operated at frequencies
of around 300 MHz. It was developed at the Bomber Support Development Unit in Worcestershire
.
Unfortunately for the RAF, the Germans
quickly developed a passive radar receiver
, Flensburg (FuG 227), which was used by Luftwaffe
nightfighters from Spring 1944 onward to home in on bombers using Monica. On the morning of 13 July 1944, a Junkers Ju 88
G-1 nightfighter equipped with Flensburg mistakenly landed at RAF Woodbridge
. After examining the Flensburg equipment, the RAF ordered Monica withdrawn from all Bomber Command
aircraft.
Monica was also used by the U.S. Army Air Corps as the AN/APS-13, where it was also used as the radar altimeter
for the Little Boy
atomic bomb dropped on Hiroshima
.
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...
for bombers, introduced by the 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...
in the spring of 1942. Officially known as ARI 5664, it operated at frequencies
Frequency
Frequency is the number of occurrences of a repeating event per unit time. It is also referred to as temporal frequency.The period is the duration of one cycle in a repeating event, so the period is the reciprocal of the frequency...
of around 300 MHz. It was developed at the Bomber Support Development Unit in Worcestershire
Worcestershire
Worcestershire is a non-metropolitan county, established in antiquity, located in the West Midlands region of England. For Eurostat purposes it is a NUTS 3 region and is one of three counties that comprise the "Herefordshire, Worcestershire and Warwickshire" NUTS 2 region...
.
Unfortunately for the RAF, the Germans
Nazi Germany
Nazi Germany , also known as the Third Reich , but officially called German Reich from 1933 to 1943 and Greater German Reich from 26 June 1943 onward, is the name commonly used to refer to the state of Germany from 1933 to 1945, when it was a totalitarian dictatorship ruled by...
quickly developed a passive radar receiver
Receiver (radio)
A radio receiver converts signals from a radio antenna to a usable form. It uses electronic filters to separate a wanted radio frequency signal from all other signals, the electronic amplifier increases the level suitable for further processing, and finally recovers the desired information through...
, Flensburg (FuG 227), which was used by Luftwaffe
Luftwaffe
Luftwaffe is a generic German term for an air force. It is also the official name for two of the four historic German air forces, the Wehrmacht air arm founded in 1935 and disbanded in 1946; and the current Bundeswehr air arm founded in 1956....
nightfighters from Spring 1944 onward to home in on bombers using Monica. On the morning of 13 July 1944, a Junkers Ju 88
Junkers Ju 88
The Junkers Ju 88 was a World War II German Luftwaffe twin-engine, multi-role aircraft. Designed by Hugo Junkers' company through the services of two American aviation engineers in the mid-1930s, it suffered from a number of technical problems during the later stages of its development and early...
G-1 nightfighter equipped with Flensburg mistakenly landed at RAF Woodbridge
RAF Woodbridge
Royal Air Force Station Woodbridge, more commonly referred to as RAF Woodbridge, is a former Royal Air Force military airbase situated to the east of Woodbridge in the county of Suffolk, England...
. After examining the Flensburg equipment, the RAF ordered Monica withdrawn from all 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...
aircraft.
Monica was also used by the U.S. Army Air Corps as the AN/APS-13, where it was also used as the radar altimeter
Radar altimeter
A radar altimeter, radio altimeter, low range radio altimeter or simply RA measures altitude above the terrain presently beneath an aircraft or spacecraft...
for the Little Boy
Little Boy
"Little Boy" was the codename of the atomic bomb dropped on Hiroshima on August 6, 1945 by the Boeing B-29 Superfortress Enola Gay, piloted by Colonel Paul Tibbets of the 393rd Bombardment Squadron, Heavy, of the United States Army Air Forces. It was the first atomic bomb to be used as a weapon...
atomic bomb dropped on Hiroshima
Hiroshima
is the capital of Hiroshima Prefecture, and the largest city in the Chūgoku region of western Honshu, the largest island of Japan. It became best known as the first city in history to be destroyed by a nuclear weapon when the United States Army Air Forces dropped an atomic bomb on it at 8:15 A.M...
.