Yellow Duckling was an early development of an
infrared linescan camera, developed for the detection of submarines during the
Cold War
The Cold War is a term commonly used to refer to a period of geopolitical tension between the United States and the Soviet Union and their respective allies, the Western Bloc and the Eastern Bloc. The term '' cold war'' is used because the ...
. The name is one of the series of British
Rainbow Codes
The Rainbow Codes were a series of code names used to disguise the nature of various British military research projects. They were mainly used by the Ministry of Supply from the end of the Second World War until 1958, when the ministry was bro ...
.
Origins
Infrared detection systems had been considered as far back as the 1930s.
During World War II, the Germans were the innovators in this field. Studies of captured FuG.280
Kielgerät from a
Ju 88G night fighter showed the use of a
lead sulphide Lead sulfide refers to two compounds containing lead and sulfur:
*Lead(II) sulfide
Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is s ...
(PbS) detector. This was developed by the British at
TRE into a
lead telluride (PbTe) detector and the use of
liquid nitrogen
Liquid nitrogen—LN2—is nitrogen in a liquid state at low temperature. Liquid nitrogen has a boiling point of about . It is produced industrially by fractional distillation of liquid air. It is a colorless, low viscosity liquid that is wide ...
cooling to improve sensitivity and extend the lower range of temperatures it could detect.
Kielgerät also demonstrated the use of a rotating
'chopper' mirror and a simple form of
boxcar integrator
A boxcar averager (alternative names are gated integrator and boxcar integrator) is an electronic test instrument that integrates the signal input voltage after a defined waiting time (trigger delay) over a specified period of time (gate width) a ...
to extract a usable signal from a
noisy detector.
These early detectors had no scanning or imaging ability: they detected heat sources at a single spot. To make them militarily useful they were generally mounted as part of a 'track-follow' mount, where the detector head could be kept pointing at the target. This work would give rise to the heat-seeking air-to-air missiles such as the
Green Thistle seeker for the
de Havilland Blue Jay (later
Firestreak) and the improved
Violet Banner
Violet may refer to:
Common meanings
* Violet (color), a spectral color with wavelengths shorter than blue
* One of a list of plants known as violet, particularly:
** ''Viola'' (plant), a genus of flowering plants
Places United States
* Viol ...
seeker used on
Red Top.
Another approach being developed with these detectors was that of a
star tracker for missile navigation. The Blue Lagoon seeker was developed as part of the
Blue Sapphire
Sapphire is a precious gemstone, a variety of the mineral corundum, consisting of aluminium oxide () with trace amounts of elements such as iron, titanium, chromium, vanadium, or magnesium. The name sapphire is derived via the Latin "sa ...
and
Orange Tartan
Orange most often refers to:
*Orange (fruit), the fruit of the tree species '' Citrus'' × ''sinensis''
** Orange blossom, its fragrant flower
*Orange (colour), from the color of an orange, occurs between red and yellow in the visible spectrum
* ...
trackers for use in the
Blue Moon missile. These seekers scanned from side to side and could measure the position of target stars. It was recognised that if the tracker was turned upside down to point downwards, its scanning would build up a heat picture of the ground map.
Wake detection
Detection of submarines had so far relied on spotting them whilst surfaced. Infrared approaches aimed to spot the heat of their
exhaust, whilst running surfaced on diesel engines.
The earlier submarine detectors such as
Autolycus
In Greek mythology, Autolycus (; Ancient Greek: Αὐτόλυκος ''Autolykos'' 'the wolf itself') was a successful robber who had even the power of metamorphosing both the stolen goods and himself. He had his residence on Mount Parnassus and w ...
or
search radar would become ineffective with the Soviet shift to nuclear submarines in the 1960s; which could run submerged, without needing to
snorkel. New methods were sought with which to detect a submerged submarine.
Some of these methods detected not the submarine itself, but the disturbances it made in the sea. If its passage mixed
layers
Layer or layered may refer to:
Arts, entertainment, and media
* ''Layers'' (Kungs album)
* ''Layers'' (Les McCann album)
* ''Layers'' (Royce da 5'9" album)
*"Layers", the title track of Royce da 5'9"'s sixth studio album
*Layer, a female Maveric ...
of cold surface and underlying warm water, this would raise the apparent surface temperature slightly. This temperature change could be detected using an
infrared-sensitive thermometer. Although impossible to detect by measuring the temperature in the wake, imaging the temperature of the overall sea would show the wake as standing out from it.
Description
Yellow Duckling began with the Blue Lagoon work, using it as a sea surface scanner in an attempt to detect the disturbed wake of a submerged submarine and its heat signature. The detector element was a 6 mm PbTe square.
In 1953 the first test equipment was flown aboard a
Handley Page Hastings
The Handley Page HP.67 Hastings is a retired British troop-carrier and freight transport aircraft designed and manufactured by aviation company Handley Page for the Royal Air Force (RAF). Upon its introduction to service during September 1948, ...
, WD484. Later tests would use TG514, after WD484 was lost. These later tests were carried out around
Malta, hunting , the last of the World War II
S-class submarines still in commission. The PbTe detector was found to be capable of detecting a surfaced submarine, but not one submerged, snorkeling nor its wake.
An improved detector was developed, with a new element and new scanner. The detector element was a large 15 mm square of copper-
doped germanium
Germanium is a chemical element with the symbol Ge and atomic number 32. It is lustrous, hard-brittle, grayish-white and similar in appearance to silicon. It is a metalloid in the carbon group that is chemically similar to its group neighbors s ...
, cooled to
liquid hydrogen temperatures. This was potentially sensitive to temperature differences of 1/2000 °C. The new scanner used a diameter mirror with a
focal length
The focal length of an optical system is a measure of how strongly the system converges or diverges light; it is the inverse of the system's optical power. A positive focal length indicates that a system converges light, while a negative foca ...
. The whole assembly, mirror and detector, rotated continuously at 150rpm. Its axis was inclined at 30° to the vertical, to give a view facing forwards and slightly down. Rotation gave a sideways line scan, with the aircraft's motion scanning perpendicular to this.
The new germanium detector was no more sensitive than the earlier PbTe element, but was considered easier to use in service. Its detection results were disappointing: in 1956 trials it only detected around 20% of snorkeling submarines, even when their position was already known. It could not detect a submarine any deeper than . These were in the optimum conditions of the warm, calm Mediterranean at night, rather than the rough Atlantic of its likely service conditions.
Not significantly useful at sea,
it was used experimentally on land during the
EOKA
The Ethniki Organosis Kyprion Agoniston (EOKA; ; el, Εθνική Οργάνωσις Κυπρίων Αγωνιστών, lit=National Organisation of Cypriot Fighters) was a Greek Cypriot
Greek Cypriots or Cypriot Greeks ( el, Ελληνο� ...
armed struggle in
Cyprus during the late 1950s.
Never an important piece of equipment in ASW terms, Yellow Duckling did give rise to the very important field of
infrared linescan surveillance, which was an important military reconnaissance technique throughout the 1960s and 1970s.
Clinker
Interest in
wake detection
Wake or The Wake may refer to:
Culture
*Wake (ceremony), a ritual which takes place during some funeral ceremonies
*Wakes week, an English holiday tradition
* Parish Wake, another name of the Welsh ', the fairs held on the local parish's patron s ...
re-emerged in the early 1960s, to counter the problem of nuclear submarines. Yellow Duckling was developed further as Clinker.
The distinction between the two systems is unclear, but Clinker appears, by name, in 1962 studies.
Either Clinker, or Yellow Duckling, was required as a submarine wake detection system for part of
OR.350, the
Operational Requirement issued for a new
maritime patrol aircraft to enter service by 1968.
It was included, mounted in wing nacelles, as part of both the
BAC One-Eleven
The BAC One-Eleven (or BAC-111/BAC 1-11) was an early jet airliner produced by the British Aircraft Corporation (BAC).
Originally conceived by Hunting Aircraft as a 30-seat jet, before its merger into BAC in 1960, it was launched as an 80-se ...
and
Vickers Vanguard-based responses to OR.381 of 1964, the Interim Maritime Patrol aircraft.
See also
*
List of Rainbow Codes
References
{{Reflist, colwidth=35em, refs=
[{{Cite book
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, last=Gibson , first=Chris
, publisher=Hikoki Publications
, year=2015
, isbn=978-190210947-3
, pages=25–26
]
[{{Cite book
, title=Most Secret War
, first=R.V. , last=Jones
, authorlink=R.V. Jones
, year=1978
]
[{{Cite web
, title=Infra-Red Committee: field trials of Yellow Duckling equipment
, id=AC 13351 / WO 195/13347
, year=1954
, url=http://discovery.nationalarchives.gov.uk/details/r/C1993607
, publisher=The National Archives, Kew
]
Cold War military equipment of the United Kingdom
Military electronics of the United Kingdom
Military sensor technology
Code names