<s>
A	O
track	B-Algorithm
algorithm	I-Algorithm
is	O
a	O
radar	B-Application
and	O
sonar	B-Application
performance	O
enhancement	O
strategy	O
.	O
</s>
<s>
There	O
are	O
four	O
common	O
track	B-Algorithm
algorithms	I-Algorithm
.	O
</s>
<s>
This	O
includes	O
storage	B-General_Concept
tubes	I-General_Concept
used	O
with	O
planned	O
position	O
indicator	O
displays	O
,	O
range	O
height	O
indicator	O
displays	O
,	O
and	O
pen-plotting	O
boards	O
used	O
for	O
civilian	O
air	O
traffic	O
control	O
and	O
waterway	O
management	O
.	O
</s>
<s>
It	O
also	O
includes	O
custom	O
analog	O
computers	O
,	O
like	O
the	O
Mark	B-Device
I	I-Device
Fire	I-Device
Control	I-Device
Computer	I-Device
used	O
with	O
radar	B-Application
data	O
to	O
aim	O
guns	O
,	O
missiles	O
,	O
and	O
torpedoes	O
associated	O
with	O
military	O
air	O
traffic	O
control	O
and	O
waterway	O
management	O
.	O
</s>
<s>
Track	B-Algorithm
algorithms	I-Algorithm
were	O
migrated	O
from	O
analog	O
equipment	O
to	O
digital	O
computers	O
from	O
the	O
1950s	O
through	O
the	O
1980s	O
.	O
</s>
<s>
Modern	O
civilian	O
air	O
traffic	O
and	O
military	O
combat	O
systems	O
depend	O
upon	O
a	O
custom	O
track	B-Algorithm
algorithms	I-Algorithm
used	O
with	O
real-time	B-General_Concept
computing	I-General_Concept
slaved	O
to	O
displays	O
and	O
peripherals	O
.	O
</s>
<s>
Term	O
Meaning	O
Raw	O
video	O
Analog	O
detection	O
pulses	O
from	O
radar	B-Application
and	O
sonar	B-Application
systems	O
Track	O
A	O
symbol	O
and	O
number	O
allowing	O
operators	O
to	O
unambiguously	O
identify	O
the	O
vehicle	O
Leader	O
A	O
line	O
showing	O
where	O
the	O
vehicle	O
will	O
be	O
in	O
the	O
future	O
.	O
</s>
<s>
The	O
track	B-Algorithm
algorithm	I-Algorithm
produces	O
symbology	O
that	O
is	O
displayed	O
on	O
the	O
Plan	O
Position	O
Indicator	O
.	O
</s>
<s>
Hook	O
action	O
turns	O
off	O
the	O
cursor	O
and	O
displays	O
additional	O
information	O
from	O
the	O
track	B-Algorithm
algorithm	I-Algorithm
.	O
</s>
<s>
The	O
nearest	O
neighbor	O
track	B-Algorithm
algorithm	I-Algorithm
is	O
described	O
here	O
for	O
simplicity	O
.	O
</s>
<s>
Each	O
new	O
detection	O
reported	O
from	O
incoming	O
sensor	O
data	O
is	O
fed	O
into	O
the	O
track	B-Algorithm
algorithm	I-Algorithm
,	O
which	O
is	O
used	O
to	O
drive	O
displays	O
.	O
</s>
<s>
Track	B-Algorithm
algorithm	I-Algorithm
operation	O
depends	O
upon	O
a	O
track	O
file	O
,	O
which	O
contains	O
historical	O
track	O
data	O
,	O
and	O
a	O
computer	O
program	O
that	O
periodically	O
updates	O
the	O
track	O
file	O
.	O
</s>
<s>
Sensors	O
information	O
(	O
radar	B-Application
,	O
sonar	B-Application
,	O
and	O
transponder	O
data	O
)	O
is	O
provided	O
to	O
the	O
track	B-Algorithm
algorithm	I-Algorithm
using	O
a	O
polar	O
coordinate	O
system	O
,	O
and	O
this	O
is	O
converted	O
to	O
cartesian	O
coordinate	O
system	O
for	O
the	O
track	B-Algorithm
algorithm	I-Algorithm
.	O
</s>
<s>
The	O
track	B-Algorithm
algorithm	I-Algorithm
takes	O
one	O
of	O
four	O
actions	O
when	O
this	O
new	O
sensor	O
data	O
arrives	O
.	O
</s>
<s>
A	O
2D	O
radar	B-Application
with	O
a	O
fan	O
beam	O
produces	O
no	O
altitude	O
information	O
.	O
</s>
<s>
A	O
4D	O
radar	B-Application
with	O
a	O
pencil	O
beam	O
will	O
produce	O
radial	O
Doppler	O
velocity	O
in	O
addition	O
to	O
bearing	O
,	O
elevation	O
,	O
and	O
slant	O
range	O
.	O
</s>
<s>
Sensors	O
(	O
radar	B-Application
)	O
scan	O
a	O
volume	O
of	O
space	O
periodically	O
.	O
</s>
<s>
Birds	O
,	O
insects	O
,	O
trees	O
,	O
waves	O
,	O
and	O
storms	O
generate	O
enough	O
sensor	O
data	O
to	O
slow	O
down	O
the	O
track	B-Algorithm
algorithm	I-Algorithm
.	O
</s>
<s>
Excessive	O
false	O
tracks	O
degrade	O
performance	O
because	O
the	O
track	B-Algorithm
algorithm	I-Algorithm
loading	O
will	O
cause	O
it	O
to	O
fail	O
to	O
update	O
all	O
of	O
the	O
information	O
in	O
the	O
track	O
file	O
before	O
sensors	O
begin	O
the	O
next	O
scan	O
begins	O
.	O
</s>
<s>
Moving	O
target	O
indication	O
(	O
MTI	O
)	O
is	O
typically	O
used	O
to	O
reduce	O
false	O
clutter	O
tracks	O
to	O
avoid	O
overwhelming	O
the	O
track	B-Algorithm
algorithm	I-Algorithm
.	O
</s>
<s>
Lock	O
and	O
radial	O
velocity	O
are	O
unique	O
requirement	O
for	O
Doppler	O
sensors	O
that	O
add	O
additional	O
layers	O
of	O
complexity	O
to	O
the	O
track	B-Algorithm
algorithm	I-Algorithm
.	O
</s>
<s>
Invalid	O
signals	O
include	O
microwaves	O
made	O
by	O
sources	O
separate	O
from	O
the	O
transmitter	O
,	O
such	O
as	O
radar	B-Application
jamming	O
and	O
deception	O
.	O
</s>
<s>
This	O
is	O
essential	O
for	O
semi-active	O
radar	B-Application
homing	O
that	O
requires	O
velocity	O
information	O
obtained	O
by	O
the	O
launch	O
platform	O
radar	B-Application
.	O
</s>
<s>
Distance	O
is	O
identified	O
using	O
parallax	B-Device
.	O
</s>
<s>
This	O
strategy	O
is	O
normally	O
used	O
with	O
semi-active	O
radar	B-Application
homing	O
and	O
with	O
underwater	O
systems	O
.	O
</s>
<s>
Civilian	O
air	O
traffic	O
control	O
personnel	O
use	O
leaders	O
produced	O
by	O
the	O
track	B-Algorithm
algorithm	I-Algorithm
to	O
alert	O
pilots	O
when	O
the	O
future	O
position	O
of	O
two	O
tracks	O
violate	O
the	O
separation	O
limit	O
.	O
</s>
