<s>
The	O
AN/SPG	B-Algorithm
-55	I-Algorithm
was	O
an	O
American	O
tracking	O
/	O
illumination	O
radar	B-Application
for	O
Terrier	O
and	O
RIM-67	O
Standard	O
missiles	O
(	O
SM-1ER/SM	O
-2ER	O
)	O
.	O
</s>
<s>
It	O
was	O
controlled	O
by	O
a	O
UNIVAC	B-Device
1218	I-Device
computer	O
.	O
</s>
<s>
The	O
AN/SPG	O
-55B	O
antenna	O
assembly	O
consists	O
of	O
two	O
separate	O
antennas	O
:	O
the	O
main	O
antenna	O
,	O
which	O
provides	O
the	O
track	O
beam	O
,	O
guidance	O
beam	O
,	O
and	O
cwi	B-Algorithm
beam	O
,	O
and	O
the	O
capture	O
antenna	O
,	O
which	O
provides	O
the	O
capture	O
beam	O
.	O
</s>
<s>
The	O
capture-guidance	O
mode	O
is	O
employed	O
for	O
control	O
of	O
beam-riding	O
missiles	O
,	O
and	O
the	O
track	O
cwi	B-Algorithm
mode	O
is	O
used	O
for	O
semi-active	O
radar	B-Application
homing	O
(	O
SARH	O
)	O
missiles	O
.	O
</s>
<s>
This	O
provides	O
the	O
rear	O
reference	O
beam	O
,	O
which	O
provides	O
the	O
missile	O
with	O
identification	O
of	O
the	O
proper	O
illumination	O
radar	B-Application
.	O
</s>
