Lowrance electronic LMS-480M, LMS-480DF ASP Advanced Signal Processing, To change the ASP level

Section 4: Sonar Options & Other Features

Material in this section is arranged in alphabetical order.

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 automatic feature gives you the best display pos- sible 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 such as bilge pumps, engine ignition systems and wiring, air bubbles passing over the face of the transducer, even vibration from the engine. 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. However, if you are having trouble with noise, we suggest that you take steps to find the interference source and fix it, rather than continually using the unit with the 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.

At left, Sonar Menu with Sonar Features selected. In the Sonar

Features menu, Noise Rejection is selected with ASP in the default low setting (center, dual-frequency menu; at right, single-frequency menu).

To change the ASP level:

1.From the Sonar Page, press MENU↓ to SONAR FEATURESENT.

2.Press ↓ to NOISE REJECTIONENT.

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