<s>
Scalloping	O
is	O
a	O
radar	B-Application
phenomenon	O
that	O
reduces	O
sensitivity	O
for	O
certain	O
distance	O
and	O
velocity	O
combinations	O
.	O
</s>
<s>
The	O
name	O
is	O
derived	O
from	O
the	O
appearance	O
of	O
areas	O
that	O
are	O
scooped	O
out	O
of	O
graphs	O
that	O
indicate	O
radar	B-Application
sensitivity	O
.	O
</s>
<s>
There	O
are	O
two	O
different	O
types	O
of	O
radar	B-Algorithm
scalloping	I-Algorithm
.	O
</s>
<s>
Intra-pulse	O
radar	B-Algorithm
scalloping	I-Algorithm
begins	O
to	O
become	O
a	O
concern	O
above	O
the	O
following	O
velocity	O
.	O
</s>
<s>
Scalloping	O
occurs	O
at	O
150km/s	O
for	O
an	O
L-band	O
radar	B-Application
with	O
a	O
1	O
microsecond	O
pulse	O
.	O
</s>
<s>
Inter-pulse	O
radar	B-Algorithm
scalloping	I-Algorithm
involves	O
two	O
types	O
of	O
systems	O
.	O
</s>
<s>
Radar	B-Algorithm
scalloping	I-Algorithm
for	O
MTI	O
radar	B-Application
begins	O
to	O
become	O
a	O
concern	O
when	O
the	O
radial	O
velocity	O
is	O
greater	O
than	O
the	O
following	O
value	O
.	O
</s>
<s>
This	O
occurs	O
near	O
multiples	O
of	O
15m/s	O
for	O
an	O
L-Band	O
radar	B-Application
with	O
pulse	O
repetition	O
frequency	O
of	O
1kHz	O
(	O
10m/s	O
to	O
20m/s	O
,	O
25m/s	O
to	O
35m/s	O
,	O
40m/s	O
to	O
50m/s	O
,	O
and	O
so	O
on	O
)	O
.	O
</s>
<s>
Scalloping	O
for	O
pulse-Doppler	B-Algorithm
radar	I-Algorithm
involves	O
blind	O
velocities	O
created	O
by	O
the	O
clutter	O
rejection	O
filter	O
.	O
</s>
<s>
This	O
can	O
include	O
frequency	O
or	O
phase	O
shifting	O
associated	O
with	O
pulse	B-Algorithm
compression	I-Algorithm
.	O
</s>
<s>
Moving	O
target	O
indicator	O
(	O
MTI	O
)	O
radar	B-Application
reduces	O
the	O
impact	O
of	O
blind	O
velocity	O
by	O
using	O
redundant	O
detectors	O
that	O
introduce	O
a	O
compensating	O
reverse	O
phase	O
shift	O
undoes	O
the	O
phase	O
shift	O
caused	O
by	O
Doppler	O
from	O
reflector	O
motion	O
.	O
</s>
<s>
Pulse-Doppler	B-Algorithm
radar	I-Algorithm
systems	O
compensate	O
using	O
3	O
or	O
more	O
different	O
pulse	O
repetition	O
frequency	O
in	O
the	O
detection	O
scheme	O
.	O
</s>
