Matt-According to RAF Upwood, it was used by the RAF as a tail warning device that provided CRT information of aircraft approaching from behind and below., if thats any help!! How or who worked it ,i havent got a clue!
Hi Matt Monica was a short-lived radar device fitted in the tail of the Heavies to give warning of the approach from the rear of another A/C.It was introduced in 1942 but the Germans devised a receiver to pick up the transmissions (Flensburg) and fitted it to night fighters.Bomber Command found this out when a Ju88,fitted with the receiver, landed by mistake in the UK. Monica was then withdrawn.Wikipaedia has some info. Dick
Hope that the following text from AIR14/1864 helps;
MONICA I (AURAL MONICA) gives warning of the approach of aircraft inside a volume, approximately a hemisphere, to the rear of the bomber. It has a maximum range astern normally set to 600, 800 or 1000 yds. and a smaller range on the beams or directly above or below. The warning is in the form of pips on the intercom and is heard by all members of the crew. The speed of the pipping increases as the other aircraft approaches, so that an idea of the range is obtained. MONICA I provides no identification, no information on the direction of the approaching aircraft, or whether there are more than one (the rate of the pipping applies to the nearest).
MONICA III (VISUAL MONICA, FISHCAKE) has the same angular cover as MONICA I, with a rearward maximum range of 7,000 yds. The presentation unit is a single cathode ray tube on which each aircraft within range appears as a blip extending either side of a vertical time base. The distance of the blip from the bottom of the trace represents the range (the tube is normally calibrated at 500 yd. intervals). The ground return prevents aircraft being seen at distances greater than the bomber's height. The azimuth of the aircraft causing the blip is shown by the ratio of the right and left hand parts of the blip. Thus 2:1 right would mean an aircraft about 20o to starboard. There is no indication of elevation and the only identification that can be attempted is by speed of approach and its behaviour during evasive action. There is a minimum range to the equipment as well as a maximum. When aircraft approach within about 300 yds. they can no longer be picked out on the screen. Normally however, a turn off track or a combat manoeuvre is started well outside this range (700-1000 yds). The presentation units of MONICA II and V (and also FISHPOND) are fixed on the wireless operator's table and he is responsible for watching them and giving instructions.
MONICA V (A.I. IV, LULU) has similar characteristics to MONICA III, but has an additional cathode ray tube giving elevation. On this second tube the aircraft appears as a blip above and below a horizontal time base, the position on the trace corresponding to range and the ratio of the two parts of the blip showing the angle above or below the horizontal.
Boozer and Fishpond were two other types of warning device. I can post their descriptions also if required. Regards Mike
-- Edited by mikew156 on Tuesday 25th of August 2009 06:28:12 AM
Linda R Ibrom
