<s>
Radar	O
envelope	B-Algorithm
is	O
a	O
critical	O
Measure	O
of	O
Performance	O
(	O
MOP	O
)	O
identified	O
in	O
the	O
Test	O
and	O
Evaluation	O
Master	O
Plan	O
(	O
TEMP	O
)	O
.	O
</s>
<s>
The	O
ambiguity	B-Algorithm
function	I-Algorithm
associated	O
with	O
pulse	B-Algorithm
compression	I-Algorithm
and	O
scalloping	B-Algorithm
associated	O
with	O
moving	O
target	O
indication	O
are	O
two	O
examples	O
.	O
</s>
<s>
Radar	O
system	O
specifications	O
require	O
a	O
specific	O
level	O
of	O
performance	O
within	O
a	O
specific	O
radar	O
envelope	B-Algorithm
.	O
</s>
<s>
Data	B-General_Concept
is	I-General_Concept
extracted	I-General_Concept
and	O
recorded	O
from	O
the	O
radar	O
system	O
while	O
aircraft	O
,	O
balloons	O
,	O
ships	O
,	O
drones	O
,	O
missiles	O
or	O
other	O
objects	O
are	O
moved	O
within	O
the	O
radar	O
envelope	B-Algorithm
.	O
</s>
<s>
The	O
recorded	O
data	O
is	O
compared	O
to	O
distance	O
,	O
altitude	B-Application
,	O
and	O
speed	O
of	O
the	O
objects	O
to	O
evaluate	O
the	O
pass-fail	O
criteria	O
.	O
</s>
<s>
These	O
are	O
the	O
typical	O
shapes	O
of	O
the	O
physical	O
radar	O
envelope	B-Algorithm
.	O
</s>
<s>
Nap-of-the-earth	O
flying	O
techniques	O
can	O
be	O
used	O
to	O
avoid	O
detection	O
when	O
the	O
blind	O
range	O
exceeds	O
the	O
radar	B-Algorithm
horizon	I-Algorithm
.	O
</s>
<s>
Altitude	B-Application
is	O
the	O
distance	O
from	O
the	O
earth	O
surface	O
.	O
</s>
<s>
There	O
are	O
two	O
difficulties	O
associated	O
with	O
altitude	B-Application
.	O
</s>
<s>
The	O
radiation	B-Device
pattern	I-Device
of	O
a	O
rotating	O
truncated	O
parabolic	O
antenna	O
for	O
radar	O
fixed	O
pedestal	O
has	O
a	O
fan	O
shaped	O
beam	O
with	O
a	O
vertical	O
gap	O
in	O
coverage	O
.	O
</s>
<s>
Pulse-Doppler	B-Algorithm
radar	I-Algorithm
and	O
Continuous-wave	B-Algorithm
radar	I-Algorithm
are	O
required	O
for	O
high	O
performance	O
in	O
this	O
area	O
because	O
these	O
exclude	O
low-velocity	O
reflections	O
.	O
</s>
<s>
MTI	O
creates	O
blind	O
velocities	O
associated	O
with	O
radar	B-Algorithm
scalloping	I-Algorithm
.	O
</s>
