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The range and the bearing to the target location appear in

the upper-left corner of the screen.

Radar Overlay

When you connect your chartplotter to an optional Garmin

marine radar, you can use the Radar overlay to overlay radar

information on the Navigation chart or on the Fishing chart.

The Radar overlay superimposes radar information on the

Navigation chart or the Fishing chart. Data appears on the

Radar overlay based on the most recently used radar mode

(such as Harbor, Offshore, or Sentry), and all settings

configurations applied to the Radar overlay are also applied to

the last-used radar mode. For example, if you use Harbor mode

and then you switch to the Radar overlay, the Radar overlay

would show Harbor mode radar data. If you changed the gain

setting using the Radar overlay menu, the gain setting for

Harbor mode would change automatically.

Radar Overlay and Chart Data Alignment

When using the Radar overlay, the chartplotter aligns radar data

with chart data based on the boat heading, which is based by

default on data from a magnetic heading sensor connected

using a NMEA 0183 or NMEA 2000 network. If a heading

sensor is not available, the boat heading is based on GPS

tracking data.

GPS tracking data indicates the direction in which the boat is

moving, not the direction in which the boat is pointing. If the

boat is drifting backward or sideways due to a current or wind,

the Radar overlay may not perfectly align with the chart data.

This situation should be avoided by using boat-heading data

from an electronic compass.

If the boat heading is based on data from a magnetic heading

sensor or an automatic pilot, the heading data could be

compromised due to incorrect setup, mechanical malfunction,

magnetic interference, or other factors. If the heading data is

compromised, the Radar overlay may not align perfectly with

the chart data.

Showing the Radar Overlay

The Radar overlay displays data based on the most recently

used radar mode.

From a Radar screen, select Menu > Radar Menu >

Change Radar > Radar Overlay.

The radar picture appears in orange and overlays the

Navigation chart.

Stopping the Transmission of Radar Signals

From a Radar screen, select Menu > Radar Menu > Radar

to Standby.

Optimizing the Radar Display

You can adjust the radar display settings for reduced clutter and

increased accuracy.

NOTE: You can optimize the radar display for each radar mode.

Select a radar range

(page

Restore the default value of the gain setting

Adjust the gain setting manually

Range of Radar Signals

The range of the radar signal indicates the length of the pulsed

signal transmitted and received by the radar. As the range

increases, the radar transmits longer pulses in order to reach

distant targets. Closer targets, especially rain and waves, also

reflect the longer pulses, which can add noise to the Radar

screen. Viewing information about longer-range targets can also

decrease the amount of space available on the Radar screen

for viewing information about shorter-range targets.

14).

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14).

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14).

Radar Gain and Clutter

Automatically Adjusting Gain on the Radar Screen

Auto is the default value for the gain setting. The automatic gain

setting for each radar mode is optimized for that mode, and may

differ from the automatic gain setting used for another mode.

NOTE: Depending upon the radar in use, the gain setting

configured for use in one radar mode may or may not be

applied to other radar modes or to the Radar overlay.

From a Radar screen or the Radar overlay, select Menu >

Radar Menu > Gain > Auto.

The chartplotter sets the gain automatically once, based on

average conditions, the range of the radar signal, and the

selected radar mode. The chartplotter does not readjust the

gain automatically in response to changing conditions.

Manually Adjusting Gain on the Radar Screen

For optimal radar performance that accounts for actual

conditions, you can manually adjust the gain.

NOTE: Depending upon the radar in use, the gain setting

configured for use in one radar mode may or may not be

applied to other radar modes or to the Radar overlay.

From a Radar screen or the Radar overlay, select Menu >

Radar Menu > Gain.

Select Up to raise the gain, until light speckles appear across

the Radar screen.

Data on the Radar screen is refreshed every few seconds.

As a result, the effects of manually adjusting the gain may

not appear instantly. Adjust the gain slowly.

Select Down to lower the gain until the speckles disappear.

If boats, land, or other targets are within range, select Down

to lower the gain until the targets begin to blink.

Select Up to raise the gain until the boats, land, or other

targets appear steadily lit on the Radar screen.

Minimize the appearance of nearby large objects, if

necessary.

Minimize the appearance of side-lobe echoes, if necessary.

Minimizing Nearby Large-Object Interference

Nearby targets of significant size, such as jetty walls, can cause

a very bright image of the target to appear on the Radar screen.

This image can obscure smaller targets located near it.

NOTE: Depending upon the radar in use, the gain setting

configured for use in one radar mode may or may not be

applied to other radar modes or to the Radar overlay.

From a Radar screen or the Radar overlay, select Menu >

Radar Menu > Gain.

Select Down to lower the gain until the smaller targets are

clearly visible on the Radar screen.

Reducing the gain to eliminate nearby large-object

interference may cause smaller or distant targets to blink or

disappear from the Radar screen.

Minimizing Side-Lobe Interference on the Radar Screen

Side-lobe interference may appear to streak outward from a

target in a semi-circular pattern. Side-lobe effects can be

avoided by reducing the gain or reducing the radar range.

NOTE: Depending upon the radar in use, the gain setting

configured for use in one radar mode may or may not be

applied to other radar modes or to the Radar overlay.

From a Radar screen or the Radar overlay, select Menu >

Radar Menu > Gain.

Select Down to lower the gain until the semi-circular,

streaked pattern disappears from the Radar screen.

Reducing the gain to eliminate side-lobe interference may

cause smaller or distant targets to blink or disappear from

the Radar screen.

Radar