How To Interpret The Radar Display; False Echoes - Furuno NavNet TZtouch3 Series Operator's Manual

6. RADAR
[Tuning Source]: For dual range display, select the range to use as the manual tuning
source. Not available (grayed out) with the radar sensor DRS4DL/DRS4DL+, DRS4D-
NXT.
[Radar Monitoring]: Show various voltage levels, and ARPA data. For the service
technician.
[Radar Optimization]: Automatically adjust magnetron output and tuning for the con-
nected radar. Be sure to do this after replacing the magnetron. Not available
(grayed out) with the radar sensor DRS4D-NXT.
[ARPA Advanced Settings]: Sets ARPA parameters. For the service technician only.
Do not change the settings. Set [TX/STBY] to [ON] to access. Not available (grayed
out) with the radar sensor DRS4DL/DRS4DL+, FAR-2xx7 series radar antenna.
[Set Hardware to Factory Default]: For the service technician only.
[Reset Default Settings]: Restore default settings for items other than those in the [RA-
DAR INITIAL SETUP] section.
6.27

How to Interpret the Radar Display

6.27.1

False echoes

Echo signals can appear on the screen at positions where there is no target or disap-
pear where there are targets. You can identify false targets when you understand why
the false echoes appear. A description of false echoes follows.
Multiple echoes
Multiple echoes occur when a transmitted pulse returns from a solid object like a large
ship, bridge, or breakwater. A second, a third or more echoes can be seen on the
screen at two, three or more times the true range of the target as shown below. You
can reduce and sometimes remove these multiple echoes if you decrease the gain, or
correctly adjust the sea clutter.
6-30
Target
Own ship
True echo
Multiple echo