Symposium on unidentified flying objects: hearings before the Committee on Science and Astronautics, U.S. House of Representatives, Ninetieth Congress, second session, July 29, 1968.

181
enhanced
by
flaring,
halation,
adjacency
effects,
etc.)
is
also
not
compatible
with the photographic
experi-
ments,
since
planes
close
enough
to
give
rise
to
the
images
shown
on
the
film
clip
would
also
exhibit
some
airplane
structure
as
shown
in
Figure
6-24,
page
323
of
reference
[3]
in
which
the
airplane
images
are
of
a
size
and
brightness
comparable
to
that
of
the
unknowns.
This
figure
is
a
blow-up
of
a
16
mm
frame from
a
camera
of
the
same
type
as Mariana's,
with
the
same
stop
setting
and
3"
telephoto
lens.
During
the
experimental
filming,
relative
Sun
angle,
weather,
etc.,
were
the
same
as
that
reported
by
Mariana
and
verified
by
the
Mon-
tana
film
itself,
except that the
jets
were
on
a
different
heading—not
171°—in
order
to obtain
optimal
Sun
reflections.
The
jet
planes
shown
in
the
figure
were
at
a
distance
of
2.5
miles
and
their
structure exhibited
angular
dimensions
of
about
4
by
1
milliradians,
whereas
their
elliptical,
Sun
-reflection flare
image
exhibited
angular
dimensions
of
about
6
by
1.4
milliradians.
Upon
close
inspection,
the
flare
included
a
roughly
circular
bright
nucleus
and
a
comet
-like
"tail"
of
lesser
brightness
about
4.4
milliradians
long.
This
comet
-like
Sun
flare,
which
is
not
exhibited
on
the
Montana
film,
is
also
generally
characteristic
of
airplane
-fuselage
Sun
reflections
having approximately the
same
brightness
as
the
Montana
film objects.
Even
with the
larger
comet
-
like
flare,
the
jets
photographed
during
the photo-graphic
experiment
are
clearly identifiable:
Finally,
airplanes
at
the
limiting
distance
for
resolution
of
struc-
ture
(over
6.5
miles),
with
the
3"
telephoto
lens
used,
would
have
to
have
been
traveling
at speeds
in
excess
of
the
capability
of
the
F
-94's
(above
600
mph
[6])
in
order
to
have
been
compatible with the
angular
rates
of
the
images
displayed
on
the
film.
At
6.5
miles
a
typical
50
foot
airplane
(such
as
an
F-94)
subtends
angles
of
1.5
x
0.4
milliradians
or
5
3
/
4
by
It
minutes
of
are.
The
resolving
power
of
the
eye
is
from
1
to
3
minutes
of
arc
(the
Moon
is
about
30
minutes
of
arc
in
angular
di-
ameter).
The
actual
resolving
power
of
the
camera
used
by
Mariana
(with
the
3"
telephoto
lens
and
set
at
f/22)
is
from
2/3rds
to
one
minute
of
arc
even
though
its
theoretical
resolving
power
(exclusive
of
aberrations)
is
on
the
order
of
2/3rds
of
a
minute
of arc
(0.19
milli
-
radians).
Thus,
theoretically,
and
as
borne
out
by
the
author's
experiments, the
F
-94's
would have
been
identifiable
even
at
6.5
miles.
The
(0.8)
(1.51)
=
1.2milliradians
fuzzy
image
(as
depicted
on
the
film
for
UFO
8
1)
would
have
somewhat
obscured
an
airplane
structure
at
this
distance;
but
the
structure
would
still
have
been
recognizable.
The
angular
(azimuthal)
velocity
of
the
objects
was
found
to
be
0.019,
2
radians/second.
Equipped
with
the
knowledge
of
the
focal
length
and
frame
speed
(16
frames
per
second)
of
Mariana's
camera
and
the
fore-
ground
during the
filming,
the
transverse
component
of
the
velocity
of
the
objects
can
be
correlated
to
their
height
above
the
local
terrain
(3,312
ft)
and
distances
from
the
observer
(for
the
objects
when
they
first
appear
on
the
film).
Since
only angular
distances
from
one
station
are
available for
measurement,
their
actual
range
cannot
be
determined.
On
the
other
hand,
Table
I
can
be
constructed
on
the
basis
of
a
variety
of
hypo-
thetical
ranges.
The
measurements
of
the
diameter
of
the developed
images
presented
in
Fig.
I
are
the
least
accurate of
all
the
data
because
of
the
smallness
of
the
dimension
and
the
fuzziness
of
the images.
The
image
of
any
brilliant
light
source
as
seen
by
either
the
eye
or
a
camera
can
appear
much
larger
than
the
source
itself.
This
fact
had
obvious
bearing
on
the
analysis
of
the
TABLE
I
Hypothetical
Range,
Heights,
and
Speeds
(Pier)
Height
,
(Feet)
_
S
T
pe
r
:
c
r,
e
n
r
p
s
r,
)
Speed
at
171°
heading
(mid1)
_Speedifsor
°Ca,
i
ll:
(mPh)
Comments0.5 690
55.
64'
Upper
limit
to
bird
speed;
Intl
birds
would have
been
re•
solved.'
2.0
2,730
158. 197.
382'
Usual
F-94 speed
in
a
landing
pattern
is
130
to
190
mph;
bit)
would
easily
have
been
resolved.
6.5
8,860 470. 600.
1,140'
Maximum(dive)
F-94 speed
is
602
mph;
but
would have
beet
resolved.
563
950,000 39,000
Low
-speed
meteors
171;
but would
not
be
detected at
thit
(290
km)
range
on
a
bright
day. Atmosphere
too
thin
above
100
kn
for bolides
or
fireballs.
2,260 5,610,000 156,000 High-speed meteors
171;
but would
not
be
detected
at
thit
(1,710
km)
range
on
a
bright
day. Atmosphere
too
thin
above
100
kn
bolides
or
fireballs.
'
Above
the
observer—Add
3,312
ft.
for absolute
altitt
de.
'Includes
20
mph
component
of
head winds.
'Ducks,
geese,
etc.
would be
flapping
or
swooping and
would not appear
like
the
objects
on
the
film
at
any
distance.