DATE: Oct/Nov 1954 TIME: approx. noon CLASS: R
ground radar
LOCATION: SOURCES: Good ATS 1987 36, United Kingdom
FSR CH 15 June 73 3 & n.p6
RADAR DURATION: unspecified
EVALUATION: No official
PRECIS: According to a War Office statement a few
days after the events, radars in an undisclosed area
of the UK registered "formations" of unidentified
echoes on 6 occasions from late October to early
November 1954. The story was covered by numerous
British and European newspapers. A government
spokesman quoted in the Sunday Dispatch, November 7,
stated:
The targets were first observed by a civilian
radar scientist, and subsequently by all radars in the
area. They always moved from E to W, always appeared
at a height of 12,000' and the same regular patterns
were repeated on all six occasions, whether the sky
was clear or cloudy. The location was kept secret, and
one operator was quoted as saying that they had
received high-level orders not to disclose
information. The Air Ministry, evidently keen to
dampen down public speculation, pointed out that there
were many possible causes of echoes on radar, such as
birds, aircraft, balloons or kites. But the
specialists involved did not think that such regular
patterns could be explained by any of these causes.
NOTES: Immediate suspects in this case are birds or
insects. Qualitatively speaking, the kind of changing
linear formations described are reminiscent of the
flight patterns of flocks of geese, for example.
During the war so-called "ring angels" were first
observed on radars near London when observers reported
nothing visible to account for them. These expanding
circles of echoes were always observed at dawn. They
were eventually traced to the dispersal of flocks of
birds from their nocturnal roosts. The flight patterns
of migrating geese can be remarkably regular, tending
to follow well-defined corridors, and the reported
time of year is not inconsistent with this hypothesis.
It is possible that different formations on successive
days might exhibit a roughly similar sequence of
flight patterns due to peculiarities of the local
topography, or to consequent wind/convection currents.
However, 12,000' is very high for geese and
statistically improbable for any flocking bird over
the UK, and if the operators' reports of invariably
regular patterns are accurate then birds are a little
improbable. It is also true that there is a marked
tendency for birds to fly at higher mean altitudes in
overcast as opposed to clear conditions, yet these
targets were reportedly always at 12,000' irrespective
of cloud cover.
Some of the larger insects can be observed on
surveillance radars, though their cross-sections are
very dependent on frequency and would not offer strong
targets except on ultra-sensitive research radars. In
this case the targets were apparently detected on "all
the radars in the area". The implied volume of insects
and the linear distributions might be a problem. The
only candidate with an inherent tendency to long,
linear distributions would be immature spiders
parachuting on strands of gossamer, a phenomenon which
does occur preferentially around October/November.
However the backscattering cross-sections of such
spiders are likely to be on the order of only 0.1 sq.
cm. or less, and the number of individual arachnids
required to yield detectable signals spanning an area
"miles long and miles wide" is presumably untenable.
Furthermore it strains credibility to imagine such
structures, drifting at the mercy of winds and
convection updraughts, rehearsing a similar ballet on
six occasions, each at the same time of day. The same
problem exists with seabreeze fronts which sometimes
display as lines of scattered echoes (due in part to
refractive discontinuities and in part to birds or
insects lofted on the air currents) and other weather
targets, such as rain or hail cells. Superrefractive
anomalous propagation of ground returns is ruled out
by the uncharacteristic target behaviour, apparent
independence from weather conditions and the several
different radars involved. Partial reflection from
travelling waves on an inversion surface at about
6000' could generate linear clusters of mobile targets
with apparent altitudes of about 12,000', but hardly
with the same distribution on six occasions and on
several different instruments.
Radio frequency interference can generate linear
speckle patterns, but the displayed product of any one
source of interference would be dependent on the
unique bandwidth, pulse repetition frequency and scan
period of the receiver among other factors. It is
therefore highly improbable that "all the radars in
the area", civil and military, would simultaneously
display RFI signals, and virtually impossible for them
all to display the same atypical patterns of blips
with the same atypical cross-scope motion - not to
mention concurrent detection on PPI scopes and, it is
to be presumed, height-finders.
Clearly more information is needed in this case.
The most probable explanation would seem to be
migrating flocks of birds, but this does involve
dismissing the specific assertions made by radar
operators that the target formations were too regular
and too accurately repeated to be due to birds.
[A curious addendum to these events is a visual
report of similar phenomena over Rome on October 30
and, especially, on November 6 & 7 1954. According
to Italian diplomat Alberto Perego, at that time
working in Rome (he was later attached to the Italian
Consulate in Belo Horizonte, Brazil) hundreds of
people watched a display of numerous small lights like
"white spots, sometimes with a short white trail"
which formed and reformed in rough geometrical
patterns resembling successively the letters 'V' and
'X', then separated into two "serpentine curves" which
moved off in different directions. Perego published
his descriptions in 1957. At the time he had been
amazed that no newspaper reports appeared, and
contacted several diplomatic colleagues and military
officials about the events. No one acknowledged having
any information. Interestingly, in view of the passing
mention above of parachuting spiders, on both
occasions Perego reports that a "shining filamentous
material" descended from the sky. It "evaporated
completely in a few hours." The connection - if any -
between this report and the radar targets observed in
Britain during the same time frame remains obscure.]
STATUS: Insufficient information
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