<s>
A	O
fire-control	B-Application
system	I-Application
(	O
FCS	O
)	O
is	O
a	O
number	O
of	O
components	O
working	O
together	O
,	O
usually	O
a	O
gun	B-Device
data	I-Device
computer	I-Device
,	O
a	O
director	O
and	O
radar	B-Application
,	O
which	O
is	O
designed	O
to	O
assist	O
a	O
ranged	O
weapon	O
system	O
to	O
target	O
,	O
track	O
,	O
and	O
hit	O
a	O
target	O
.	O
</s>
<s>
The	O
original	O
fire-control	B-Application
systems	I-Application
were	O
developed	O
for	O
ships	O
.	O
</s>
<s>
This	O
problem	O
was	O
solved	O
with	O
the	O
introduction	O
of	O
the	O
gyroscope	B-Application
,	O
which	O
corrected	O
this	O
motion	O
and	O
provided	O
sub-degree	O
accuracies	O
.	O
</s>
<s>
Coordinated	O
gunfire	O
from	O
a	O
formation	O
of	O
ships	O
at	O
a	O
single	O
target	O
was	O
a	O
focus	O
of	O
battleship	B-Application
fleet	O
operations	O
.	O
</s>
<s>
Corrections	O
are	O
made	O
for	O
surface	O
wind	O
velocity	O
,	O
firing	O
ship	O
roll	O
and	O
pitch	O
,	O
powder	O
magazine	O
temperature	O
,	O
drift	O
of	O
rifled	O
projectiles	O
,	O
individual	O
gun	O
bore	O
diameter	O
adjusted	O
for	O
shot-to-shot	O
enlargement	O
,	O
and	O
rate	O
of	O
change	O
of	O
range	O
with	O
additional	O
modifications	O
to	O
the	O
firing	B-Application
solution	I-Application
based	O
upon	O
the	O
observation	O
of	O
preceding	O
shots	O
.	O
</s>
<s>
The	O
resulting	O
directions	O
,	O
known	O
as	O
a	O
firing	B-Application
solution	I-Application
,	O
would	O
then	O
be	O
fed	O
back	O
out	O
to	O
the	O
turrets	O
for	O
laying	O
.	O
</s>
<s>
Between	O
the	O
American	O
Civil	O
War	O
and	O
1905	O
,	O
numerous	O
small	O
improvements	O
,	O
such	O
as	O
telescopic	O
sights	O
and	O
optical	O
rangefinders	B-Algorithm
,	O
were	O
made	O
in	O
fire	O
control	O
.	O
</s>
<s>
Around	O
1905	O
,	O
mechanical	O
fire	O
control	O
aids	O
began	O
to	O
become	O
available	O
,	O
such	O
as	O
the	O
Dreyer	O
Table	O
,	O
Dumaresq	B-Device
(	O
which	O
was	O
also	O
part	O
of	O
the	O
Dreyer	O
Table	O
)	O
,	O
and	O
,	O
but	O
these	O
devices	O
took	O
a	O
number	O
of	O
years	O
to	O
become	O
widely	O
deployed	O
.	O
</s>
<s>
These	O
devices	O
were	O
early	O
forms	O
of	O
rangekeepers	B-Device
.	O
</s>
<s>
Arthur	B-Application
Pollen	I-Application
and	O
Frederic	O
Charles	O
Dreyer	O
independently	O
developed	O
the	O
first	O
such	O
systems	O
.	O
</s>
<s>
To	O
this	O
he	O
added	O
a	O
gyroscope	B-Application
to	O
allow	O
for	O
the	O
yaw	O
of	O
the	O
firing	O
ship	O
.	O
</s>
<s>
Like	O
the	O
plotter	O
,	O
the	O
primitive	O
gyroscope	B-Application
of	O
the	O
time	O
required	O
substantial	O
development	O
to	O
provide	O
continuous	O
and	O
reliable	O
guidance	O
.	O
</s>
<s>
The	O
addition	O
of	O
director	O
control	O
facilitated	O
a	O
full	O
,	O
practicable	O
fire	B-Application
control	I-Application
system	I-Application
for	O
World	O
War	O
I	O
ships	O
,	O
and	O
most	O
RN	O
capital	O
ships	O
were	O
so	O
fitted	O
by	O
mid	O
1916	O
.	O
</s>
<s>
This	O
improved	O
aiming	O
and	O
larger	O
optical	O
rangefinders	B-Algorithm
improved	O
the	O
estimate	O
of	O
the	O
enemy	O
's	O
position	O
at	O
the	O
time	O
of	O
firing	O
.	O
</s>
<s>
The	O
system	O
was	O
eventually	O
replaced	O
by	O
the	O
improved	O
"	O
Admiralty	B-Device
Fire	I-Device
Control	I-Device
Table	I-Device
"	O
for	O
ships	O
built	O
after	O
1927	O
.	O
</s>
<s>
During	O
their	O
long	O
service	O
life	O
,	O
rangekeepers	B-Device
were	O
updated	O
often	O
as	O
technology	O
advanced	O
,	O
and	O
by	O
World	O
War	O
II	O
they	O
were	O
a	O
critical	O
part	O
of	O
an	O
integrated	O
fire	B-Application
control	I-Application
system	I-Application
.	O
</s>
<s>
The	O
incorporation	O
of	O
radar	B-Application
into	O
the	O
fire	B-Application
control	I-Application
system	I-Application
early	O
in	O
World	O
War	O
II	O
provided	O
ships	O
the	O
ability	O
to	O
conduct	O
effective	O
gunfire	O
operations	O
at	O
long	O
range	O
in	O
poor	O
weather	O
and	O
at	O
night	O
.	O
</s>
<s>
For	O
U.S.	O
Navy	O
gun	B-Application
fire	I-Application
control	I-Application
systems	I-Application
,	O
see	O
ship	B-Application
gun	I-Application
fire-control	I-Application
systems	I-Application
.	O
</s>
<s>
The	O
use	O
of	O
director-controlled	O
firing	O
,	O
together	O
with	O
the	O
fire	B-Application
control	I-Application
computer	I-Application
,	O
removed	O
the	O
control	O
of	O
the	O
gun	O
laying	O
from	O
the	O
individual	O
turrets	O
to	O
a	O
central	O
position	O
;	O
although	O
individual	O
gun	O
mounts	O
and	O
multi-gun	O
turrets	O
would	O
retain	O
a	O
local	O
control	O
option	O
for	O
use	O
when	O
battle	O
damage	O
limited	O
director	O
information	O
transfer	O
(	O
these	O
would	O
be	O
simpler	O
versions	O
called	O
"	O
turret	O
tables	O
"	O
in	O
the	O
Royal	O
Navy	O
)	O
.	O
</s>
<s>
Gun	O
directors	O
were	O
topmost	O
,	O
and	O
the	O
ends	O
of	O
their	O
optical	O
rangefinders	B-Algorithm
protruded	O
from	O
their	O
sides	O
,	O
giving	O
them	O
a	O
distinctive	O
appearance	O
.	O
</s>
<s>
Visual	O
range	O
measurement	O
(	O
of	O
both	O
target	O
and	O
shell	O
splashes	O
)	O
was	O
difficult	O
prior	O
to	O
availability	O
of	O
Radar	B-Application
.	O
</s>
<s>
The	O
British	O
favoured	O
coincident	O
rangefinders	B-Algorithm
while	O
the	O
Germans	O
favored	O
the	O
stereoscopic	O
type	O
.	O
</s>
<s>
Submarines	O
were	O
also	O
equipped	O
with	O
fire	B-Application
control	I-Application
computers	I-Application
for	O
the	O
same	O
reasons	O
,	O
but	O
their	O
problem	O
was	O
even	O
more	O
pronounced	O
;	O
in	O
a	O
typical	O
"	O
shot	O
"	O
,	O
the	O
torpedo	O
would	O
take	O
one	O
to	O
two	O
minutes	O
to	O
reach	O
its	O
target	O
.	O
</s>
<s>
Calculating	O
the	O
proper	O
"	O
lead	O
"	O
given	O
the	O
relative	O
motion	O
of	O
the	O
two	O
vessels	O
was	O
very	O
difficult	O
,	O
and	O
torpedo	B-Device
data	I-Device
computers	I-Device
were	O
added	O
to	O
dramatically	O
improve	O
the	O
speed	O
of	O
these	O
calculations	O
.	O
</s>
<s>
In	O
a	O
typical	O
World	O
War	O
II	O
British	O
ship	O
the	O
fire	B-Application
control	I-Application
system	I-Application
connected	O
the	O
individual	O
gun	O
turrets	O
to	O
the	O
director	O
tower	O
(	O
where	O
the	O
sighting	O
instruments	O
were	O
located	O
)	O
and	O
the	O
analogue	O
computer	O
in	O
the	O
heart	O
of	O
the	O
ship	O
.	O
</s>
<s>
Rangefinder	B-Algorithm
telescopes	O
on	O
a	O
separate	O
mounting	O
measured	O
the	O
distance	O
to	O
the	O
target	O
.	O
</s>
<s>
The	O
battleship	B-Application
during	O
a	O
1945	O
test	O
was	O
able	O
to	O
maintain	O
an	O
accurate	O
firing	B-Application
solution	I-Application
on	O
a	O
target	O
during	O
a	O
series	O
of	O
high-speed	O
turns	O
.	O
</s>
<s>
Night	O
naval	O
engagements	O
at	O
long	O
range	O
became	O
feasible	O
when	O
radar	B-Application
data	O
could	O
be	O
input	O
to	O
the	O
rangekeeper	B-Device
.	O
</s>
<s>
The	O
effectiveness	O
of	O
this	O
combination	O
was	O
demonstrated	O
in	O
November	O
1942	O
at	O
the	O
Third	O
Battle	O
of	O
Savo	O
Island	O
when	O
the	O
engaged	O
the	O
Japanese	O
battleship	B-Application
at	O
a	O
range	O
of	O
at	O
night	O
.	O
</s>
<s>
The	O
Japanese	O
during	O
World	O
War	O
II	O
did	O
not	O
develop	O
radar	B-Application
or	O
automated	O
fire	O
control	O
to	O
the	O
level	O
of	O
the	O
US	O
Navy	O
and	O
were	O
at	O
a	O
significant	O
disadvantage	O
.	O
</s>
<s>
By	O
the	O
1950s	O
gun	O
turrets	O
were	O
increasingly	O
unmanned	O
,	O
with	O
gun	O
laying	O
controlled	O
remotely	O
from	O
the	O
ship	O
's	O
control	O
centre	O
using	O
inputs	O
from	O
radar	B-Application
and	O
other	O
sources	O
.	O
</s>
<s>
The	O
last	O
combat	O
action	O
for	O
the	O
analog	O
rangekeepers	B-Device
,	O
at	O
least	O
for	O
the	O
US	O
Navy	O
,	O
was	O
in	O
the	O
1991	O
Persian	B-Application
Gulf	I-Application
War	I-Application
when	O
the	O
rangekeepers	B-Device
on	O
the	O
s	O
directed	O
their	O
last	O
rounds	O
in	O
combat	O
.	O
</s>
<s>
An	O
early	O
use	O
of	O
fire-control	B-Application
systems	I-Application
was	O
in	O
bomber	O
aircraft	O
,	O
with	O
the	O
use	O
of	O
computing	O
bombsights	B-Application
that	O
accepted	O
altitude	O
and	O
airspeed	O
information	O
to	O
predict	O
and	O
display	O
the	O
impact	O
point	O
of	O
a	O
bomb	O
released	O
at	O
that	O
time	O
.	O
</s>
<s>
The	O
best	O
known	O
United	O
States	O
device	O
was	O
the	O
Norden	B-Device
bombsight	I-Device
.	O
</s>
<s>
These	O
devices	O
used	O
a	O
gyroscope	B-Application
to	O
measure	O
turn	O
rates	O
,	O
and	O
moved	O
the	O
gunsight	O
's	O
aim-point	O
to	O
take	O
this	O
into	O
account	O
,	O
with	O
the	O
aim	O
point	O
presented	O
through	O
a	O
reflector	O
sight	O
.	O
</s>
<s>
Small	O
radar	B-Application
units	O
were	O
added	O
in	O
the	O
post-war	O
period	O
to	O
automate	O
even	O
this	O
input	O
,	O
but	O
it	O
was	O
some	O
time	O
before	O
they	O
were	O
fast	O
enough	O
to	O
make	O
the	O
pilots	O
completely	O
happy	O
with	O
them	O
.	O
</s>
<s>
The	O
first	O
implementation	O
of	O
a	O
centralized	O
fire	B-Application
control	I-Application
system	I-Application
in	O
a	O
production	O
aircraft	O
was	O
on	O
the	O
B-29	O
.	O
</s>
<s>
This	O
new	O
bomb	O
computer	O
was	O
revolutionary	O
in	O
that	O
the	O
release	O
command	O
for	O
the	O
bomb	O
was	O
given	O
by	O
the	O
computer	O
,	O
not	O
the	O
pilot	O
;	O
the	O
pilot	O
designated	O
the	O
target	O
using	O
the	O
radar	B-Application
or	O
other	O
targeting	O
system	O
,	O
then	O
"	O
consented	O
"	O
to	O
release	O
the	O
weapon	O
,	O
and	O
the	O
computer	O
then	O
did	O
so	O
at	O
a	O
calculated	O
"	O
release	O
point	O
"	O
some	O
seconds	O
later	O
.	O
</s>
<s>
Most	O
bombsights	B-Application
until	O
this	O
time	O
required	O
that	O
the	O
plane	O
maintain	O
a	O
constant	O
attitude	O
(	O
usually	O
level	O
)	O
,	O
though	O
dive-bombing	O
sights	O
were	O
also	O
common	O
.	O
</s>
<s>
The	O
principle	O
of	O
calculating	O
the	O
release	O
point	O
,	O
however	O
,	O
was	O
eventually	O
integrated	O
into	O
the	O
fire	B-Application
control	I-Application
computers	I-Application
of	O
later	O
bombers	O
and	O
strike	O
aircraft	O
,	O
allowing	O
level	O
,	O
dive	O
and	O
toss	O
bombing	O
.	O
</s>
<s>
In	O
addition	O
,	O
as	O
the	O
fire	B-Application
control	I-Application
computer	I-Application
became	O
integrated	O
with	O
ordnance	O
systems	O
,	O
the	O
computer	O
can	O
take	O
the	O
flight	O
characteristics	O
of	O
the	O
weapon	O
to	O
be	O
launched	O
into	O
account	O
.	O
</s>
<s>
By	O
the	O
start	O
of	O
World	O
War	O
II	O
,	O
aircraft	O
altitude	O
performance	O
had	O
increased	O
so	O
much	O
that	O
anti-aircraft	B-Application
guns	O
had	O
similar	O
predictive	O
problems	O
,	O
and	O
were	O
increasingly	O
equipped	O
with	O
fire-control	B-Application
computers	I-Application
.	O
</s>
<s>
The	O
early	O
versions	O
of	O
the	O
High	B-Device
Angle	I-Device
Control	I-Device
System	I-Device
,	O
or	O
HACS	B-Device
,	O
of	O
Britain	O
's	O
Royal	O
Navy	O
were	O
examples	O
of	O
a	O
system	O
that	O
predicted	O
based	O
upon	O
the	O
assumption	O
that	O
target	O
speed	O
,	O
direction	O
,	O
and	O
altitude	O
would	O
remain	O
constant	O
during	O
the	O
prediction	O
cycle	O
,	O
which	O
consisted	O
of	O
the	O
time	O
to	O
fuze	O
the	O
shell	O
and	O
the	O
time	O
of	O
flight	O
of	O
the	O
shell	O
to	O
the	O
target	O
.	O
</s>
<s>
The	O
Kerrison	B-Device
Predictor	I-Device
is	O
an	O
example	O
of	O
a	O
system	O
that	O
was	O
built	O
to	O
solve	O
laying	O
in	O
"	O
real	O
time	O
"	O
,	O
simply	O
by	O
pointing	O
the	O
director	O
at	O
the	O
target	O
and	O
then	O
aiming	O
the	O
gun	O
at	O
a	O
pointer	O
it	O
directed	O
.	O
</s>
<s>
The	O
radar-based	O
M-9/SCR	O
-584	O
Anti-Aircraft	B-Application
System	O
was	O
used	O
to	O
direct	O
air	O
defense	O
artillery	O
since	O
1943	O
.	O
</s>
<s>
The	O
MIT	O
Radiation	O
Lab	O
's	O
SCR-584	O
was	O
the	O
first	O
radar	B-Application
system	I-Application
with	O
automatic	O
following	O
,	O
Bell	O
Laboratory	O
's	O
M-9	O
was	O
an	O
electronic	O
analog	O
fire-control	B-Application
computer	I-Application
that	O
replaced	O
complicated	O
and	O
difficult-to-manufacture	O
mechanical	O
computers	O
(	O
such	O
as	O
the	O
Sperry	O
M-7	O
or	O
British	O
Kerrison	B-Device
predictor	I-Device
)	O
.	O
</s>
<s>
Although	O
listed	O
in	O
Land	O
based	O
fire	O
control	O
section	O
anti-aircraft	B-Application
fire	B-Application
control	I-Application
systems	I-Application
can	O
also	O
be	O
found	O
on	O
naval	O
and	O
aircraft	O
systems	O
.	O
</s>
<s>
In	O
the	O
United	O
States	O
Army	O
Coast	O
Artillery	O
Corps	O
,	O
Coast	O
Artillery	O
fire	B-Application
control	I-Application
systems	I-Application
began	O
to	O
be	O
developed	O
at	O
the	O
end	O
of	O
the	O
19th	O
century	O
and	O
progressed	O
on	O
through	O
World	O
War	O
II	O
.	O
</s>
<s>
It	O
was	O
only	O
later	O
in	O
World	O
War	O
II	O
that	O
electro-mechanical	O
gun	B-Device
data	I-Device
computers	I-Device
,	O
connected	O
to	O
coast	O
defense	O
radars	B-Application
,	O
began	O
to	O
replace	O
optical	O
observation	O
and	O
manual	O
plotting	O
methods	O
in	O
controlling	O
coast	O
artillery	O
.	O
</s>
<s>
Land	O
based	O
fire	B-Application
control	I-Application
systems	I-Application
can	O
be	O
used	O
to	O
aid	O
in	O
both	O
Direct	O
fire	O
and	O
Indirect	O
fire	O
weapon	O
engagement	O
.	O
</s>
<s>
Modern	O
fire-control	B-Application
computers	I-Application
,	O
like	O
all	O
high-performance	O
computers	O
,	O
are	O
digital	O
.	O
</s>
<s>
These	O
sorts	O
of	O
effects	O
are	O
noticeable	O
for	O
any	O
sort	O
of	O
gun	O
,	O
and	O
fire-control	B-Application
computers	I-Application
have	O
started	O
appearing	O
on	O
smaller	O
and	O
smaller	O
platforms	O
.	O
</s>
<s>
Tanks	O
were	O
one	O
early	O
use	O
that	O
automated	O
gun	O
laying	O
had	O
,	O
using	O
a	O
laser	O
rangefinder	B-Algorithm
and	O
a	O
barrel-distortion	O
meter	O
.	O
</s>
<s>
Fire-control	B-Application
computers	I-Application
are	O
not	O
just	O
useful	O
for	O
large	O
cannons	O
.	O
</s>
<s>
They	O
can	O
be	O
used	O
to	O
aim	O
machine	O
guns	O
,	O
small	O
cannons	O
,	O
guided	O
missiles	O
,	O
rifles	O
,	O
grenades	O
,	O
rockets	B-Application
—	O
any	O
kind	O
of	O
weapon	O
that	O
can	O
have	O
its	O
launch	O
or	O
firing	O
parameters	O
varied	O
.	O
</s>
<s>
Fire-control	B-Application
computers	I-Application
have	O
gone	O
through	O
all	O
the	O
stages	O
of	O
technology	O
that	O
computers	O
have	O
,	O
with	O
some	O
designs	O
based	O
upon	O
analogue	O
technology	O
and	O
later	O
vacuum	O
tubes	O
which	O
were	O
later	O
replaced	O
with	O
transistors	B-Application
.	O
</s>
<s>
Fire-control	B-Application
systems	I-Application
are	O
often	O
interfaced	O
with	O
sensors	O
(	O
such	O
as	O
sonar	B-Application
,	O
radar	B-Application
,	O
infra-red	O
search	O
and	O
track	O
,	O
laser	O
range-finders	O
,	O
anemometers	O
,	O
wind	O
vanes	O
,	O
thermometers	O
,	O
barometers	O
,	O
etc	O
.	O
)	O
</s>
<s>
Sonar	B-Application
,	O
radar	B-Application
,	O
IRST	O
and	O
range-finders	O
can	O
give	O
the	O
system	O
the	O
direction	O
to	O
and/or	O
distance	O
of	O
the	O
target	O
.	O
</s>
<s>
Sometimes	O
,	O
for	O
very	O
long-range	O
rockets	B-Application
,	O
environmental	O
data	O
has	O
to	O
be	O
obtained	O
at	O
high	O
altitudes	O
or	O
in	O
between	O
the	O
launching	O
point	O
and	O
the	O
target	O
.	O
</s>
<s>
Once	O
the	O
firing	B-Application
solution	I-Application
is	O
calculated	O
,	O
many	O
modern	O
fire-control	B-Application
systems	I-Application
are	O
also	O
able	O
to	O
aim	O
and	O
fire	O
the	O
weapon(s )	O
.	O
</s>
<s>
In	O
most	O
aircraft	O
the	O
aiming	O
cue	O
takes	O
the	O
form	O
of	O
a	O
"	O
pipper	O
"	O
which	O
is	O
projected	O
on	O
the	O
heads-up	B-Application
display	I-Application
(	O
HUD	B-Application
)	O
.	O
</s>
<s>
In	O
the	O
case	O
of	O
a	O
missile	O
launch	O
,	O
the	O
fire-control	B-Application
computer	I-Application
may	O
give	O
the	O
pilot	O
feedback	O
about	O
whether	O
the	O
target	O
is	O
in	O
range	O
of	O
the	O
missile	O
and	O
how	O
likely	O
the	O
missile	O
is	O
to	O
hit	O
if	O
launched	O
at	O
any	O
particular	O
moment	O
.	O
</s>
