Eagle Electronics 250i Fish Finder User Manual


 
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Section 4: Sonar Options & Features
ASP (Advanced Signal Processing)
The ASP feature is a noise rejection system built into the sonar unit
that constantly evaluates the effects of boat speed, water conditions
and interference. This feature automatically gives you the best display
possible under most conditions.
The ASP feature is an effective tool in combating noise. In sonar terms,
noise is any undesired signal. It is caused by electrical and mechanical
sources like bilge pumps, engine vibration, ignition systems, wiring and
air bubbles passing over the face of the transducer. In all cases, noise
can produce unwanted marks on the display.
The ASP feature has four settings — Off, Low, Medium and High. If
you have high noise levels, try using the High ASP setting. If, however,
you are having trouble with noise, we suggest you take steps to find the
interference source and fix it rather than continually using the unit
with a high ASP setting.
There are times when you may want to turn the ASP feature off. This
allows you to view all incoming echoes before they are processed by the
ASP feature.