Lowrance Elite FS 7 User Manual page 215

Misalignment that is not corrected for will compromise target
tracking and can result in dangerous misinterpretation of potential
navigation hazards.
Any inaccuracy will be evident when using MARPA or chart overlay.
1
Point the vessel towards a stationary isolated object, or
towards a far range AIS target where the AIS icon matches
the radar echo.
2
Adjust the coarse and fine bearing alignment so that the
heading line touches the end of the selected object, or the
radar target matches the AIS target.
Sidelobe suppression
Occasionally false target returns can occur adjacent to strong target
returns such as large ships or container ports. This occurs because
not all of the transmitted radar energy can be focused into a single
beam by the radar antenna, a small amount of energy is transmitted
in other directions. This energy is referred to as sidelobe energy and
occurs in all radar systems. The returns caused by sidelobes tend to
appear as arcs.
Ú Note:
This control should only be adjusted by experienced
radar users. Target loss in harbor environments may occur if this
control is not adjusted correctly.
When the radar is mounted where there are metallic objects near
the radar, sidelobe energy increases because the beam focus is
degraded. The increased sidelobe returns can be eliminated using
the sidelobe suppression control.
By default, this control is set to auto and normally should not need
to be adjusted. However, if there is significant metallic clutter
around the radar, sidelobe suppression may need to be increased.
To adjust the sidelobe suppression value:
1.
Set radar range to between 1/2 nm to 1 nm and the sidelobe
suppression to auto
2.
Take the vessel to a location where sidelobe returns are likely to
be seen. Typically, this would be near a large ship, container
port, or metal bridge.
3.
Traverse the area until the strongest sidelobe returns are seen.
4.
Change auto sidelobe suppression to OFF, then adjust the
sidelobe suppression control just enough to eliminate the
System setup| ELITE FS User Manual
215