<s>
SAMV	B-Algorithm
(	O
iterative	O
sparse	B-Algorithm
asymptotic	I-Algorithm
minimum	I-Algorithm
variance	I-Algorithm
)	O
is	O
a	O
parameter-free	O
superresolution	B-Algorithm
algorithm	O
for	O
the	O
linear	O
inverse	O
problem	O
in	O
spectral	O
estimation	O
,	O
direction-of-arrival	B-Algorithm
(	O
DOA	O
)	O
estimation	O
and	O
tomographic	B-Algorithm
reconstruction	I-Algorithm
with	O
applications	O
in	O
signal	O
processing	O
,	O
medical	B-Application
imaging	I-Application
and	O
remote	B-Application
sensing	I-Application
.	O
</s>
<s>
Applications	O
include	O
synthetic-aperture	B-Application
radar	I-Application
,	O
computed	O
tomography	O
scan	O
,	O
and	O
magnetic	O
resonance	O
imaging	O
(	O
MRI	O
)	O
.	O
</s>
<s>
The	O
formulation	O
of	O
the	O
SAMV	B-Algorithm
algorithm	O
is	O
given	O
as	O
an	O
inverse	O
problem	O
in	O
the	O
context	O
of	O
DOA	O
estimation	O
.	O
</s>
<s>
Suppose	O
an	O
-element	O
uniform	B-Algorithm
linear	I-Algorithm
array	I-Algorithm
(	O
ULA	O
)	O
receive	O
narrow	O
band	O
signals	O
emitted	O
from	O
sources	O
located	O
at	O
locations	O
,	O
respectively	O
.	O
</s>
<s>
To	O
estimate	O
the	O
parameter	O
from	O
the	O
statistic	O
,	O
we	O
develop	O
a	O
series	O
of	O
iterative	O
SAMV	B-Algorithm
approaches	O
based	O
on	O
the	O
asymptotically	O
minimum	O
variance	O
criterion	O
.	O
</s>
<s>
To	O
overcome	O
this	O
resolution	O
limitation	O
imposed	O
by	O
the	O
grid	O
,	O
the	O
grid-free	O
SAMV-SML	O
(	O
iterative	O
Sparse	B-Algorithm
Asymptotic	I-Algorithm
Minimum	I-Algorithm
Variance	I-Algorithm
-	O
Stochastic	O
Maximum	O
Likelihood	O
)	O
is	O
proposed	O
,	O
which	O
refine	O
the	O
location	O
estimates	O
by	O
iteratively	O
minimizing	O
a	O
stochastic	O
maximum	O
likelihood	O
cost	O
function	O
with	O
respect	O
to	O
a	O
single	O
scalar	O
parameter	O
.	O
</s>
<s>
A	O
typical	O
application	O
with	O
the	O
SAMV	B-Algorithm
algorithm	O
in	O
SISO	O
radar/sonar	O
range-Doppler	B-Algorithm
imaging	I-Algorithm
problem	O
.	O
</s>
<s>
This	O
imaging	O
problem	O
is	O
a	O
single-snapshot	O
application	O
,	O
and	O
algorithms	O
compatible	O
with	O
single-snapshot	O
estimation	O
are	O
included	O
,	O
i.e.	O
,	O
matched	O
filter	O
(	O
MF	O
,	O
similar	O
to	O
the	O
periodogram	O
or	O
backprojection	B-Algorithm
,	O
which	O
is	O
often	O
efficiently	O
implemented	O
as	O
fast	O
Fourier	O
transform	O
(	O
FFT	O
)	O
)	O
,	O
IAA	O
,	O
and	O
a	O
variant	O
of	O
the	O
SAMV	B-Algorithm
algorithm	O
(	O
SAMV-0	O
)	O
.	O
</s>
<s>
The	O
simulation	O
conditions	O
are	O
identical	O
to	O
:	O
A	O
-element	O
polyphase	O
pulse	B-Algorithm
compression	I-Algorithm
P3	O
code	O
is	O
employed	O
as	O
the	O
transmitted	O
pulse	O
,	O
and	O
a	O
total	O
of	O
nine	O
moving	O
targets	O
are	O
simulated	O
.	O
</s>
<s>
The	O
SAMV-0	O
approach	O
provides	O
highly	O
sparse	O
result	O
and	O
eliminates	O
the	O
smearing	O
effects	O
completely	O
,	O
but	O
it	O
misses	O
the	O
weak	O
dB	O
targets	O
.	O
</s>
<s>
An	O
open	O
source	O
MATLAB	B-Language
implementation	O
of	O
SAMV	B-Algorithm
algorithm	O
could	O
be	O
downloaded	O
.	O
</s>
