Raymarine Marine GPS System - Manual (Page 101)

RayTech Navigator User’s Guide
5-10
Controls to Adjust the Radar Picture
Control Option Function Default Setting
GAIN GAIN
SEA
RAIN
FTC
Controls the strength of the target returns
Reduces sea returns
Reduces close rain or snow returns
Reduces distant rain or snow returns
AUTO
AUTO-HARBOR
OFF
OFF
SEA SEA Reduces sea returns AUTO-HARBOR
MULTI TUNE Fine tunes the receiver AUTO
TARGETS INT REJ
EXPANSION
WAKES
Turns interference rejection on/off
Turns target expansion on/off
Turns wakes on/off and selects wakes length
ON
OFF
OFF
Identifying False Echo Returns
Not all echoes are direct returns to the radar antenna. Occasionally
signals appear at positions where there is no actual target. These are
called false echoes, and may be caused by side lobes, ghost images,
indirect echoes or multiple echoes.
This subsection briefly describes the echo patterns that can be
produced by false echoes and the likely cause. It should be noted that
the radar operator, through observation, practice, and experience, can
generally detect these conditions very quickly. These effects can
usually be minimized using the radar controls.