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RADAR AND ARPA MANUAL
the position of the fine tuning control. A land echo is
chosen because it will give a constant response against
which to judge the setting. If, for example, the echo of a
buoy were chosen, the observer would be unable to tell
the difference between fluctuations due to movement of
the buoy in a seaway and those due to adjustment of the
control.
Alternative acceptable criteria involve adjusting the
control to achieve:
1 The maximum radial extent of sea clutter echoes.
These are described in Section 3.6.
2 The maximum area of precipitation echoes. These are
described in Section 3.7.
3 The maximum extent of the receive ...