<s>
Side-looking	B-Algorithm
airborne	I-Algorithm
radar	I-Algorithm
(	O
SLAR	B-Algorithm
)	O
is	O
an	O
aircraft	O
-	O
or	O
satellite-mounted	O
imaging	B-Algorithm
radar	I-Algorithm
pointing	O
perpendicular	O
to	O
the	O
direction	O
of	O
flight	O
(	O
hence	O
side-looking	O
)	O
.	O
</s>
<s>
SLAR	B-Algorithm
can	O
be	O
fitted	O
with	O
a	O
standard	O
antenna	O
(	O
real	O
aperture	O
radar	O
)	O
or	O
an	O
antenna	O
using	O
synthetic	B-Application
aperture	I-Application
.	O
</s>
<s>
The	O
range	O
resolution	O
(	O
the	O
ability	O
to	O
separate	O
the	O
pixels	O
of	O
the	O
image	O
perpendicular	O
to	O
the	O
direction	O
of	O
flight	O
)	O
of	O
a	O
SLAR	B-Algorithm
depends	O
on	O
the	O
length	O
of	O
the	O
transmitted	O
pulse	O
.	O
</s>
<s>
This	O
limitation	O
can	O
be	O
overcome	O
using	O
intra-pulse	B-Algorithm
modulation	I-Algorithm
.	O
</s>
<s>
It	O
is	O
apparent	O
that	O
SLAR	B-Algorithm
antennas	O
as	O
real	O
aperture	O
could	O
not	O
be	O
built	O
large	O
enough	O
to	O
achieve	O
the	O
desired	O
azimuth	O
resolution	O
.	O
</s>
<s>
In	O
fact	O
,	O
SLAR	B-Algorithm
was	O
never	O
feasible	O
to	O
be	O
used	O
in	O
space	O
because	O
the	O
antennas	O
would	O
be	O
too	O
large	O
and	O
their	O
launch	O
in	O
space	O
too	O
expensive	O
.	O
</s>
<s>
Synthetic	B-Application
aperture	I-Application
radar	I-Application
refers	O
to	O
a	O
method	O
for	O
improving	O
the	O
azimuth	O
resolution	O
(	O
not	O
range	O
resolution	O
)	O
.	O
</s>
