Furuno MODEL 1622 - Manual (Page 19)

11
1.22 Echo Stretch
On long ranges target echoes tend to shrink in
the range direction, making them difficult to see.
On short and medium ranges such as 1.5, 3 and
6 nm range scales, the same sized targets get
smaller on screen as they approach own ship.
This is due to the inherent property of the
radiation pattern produced by the antenna. To
enhance target video, use the echo stretch
feature.
Echo
stretched
in range
direction
Echo
Echo stretch OFF Echo stretch ON
ES
Echo stretch
ON
Figure 1-21 Echo stretch
1. Press the [MENU] key.
2. Select ECHO STRETCH.
3. Select ON or OFF.
4. Press the [MENU] key.
ES appears at the top right corner on the screen
when the echo stretch feature is on.
Note 1: Echo stretch magnifies not only small
target pips but also returns from sea surface,
rain and radar interference. For this reason,
make sure that these types of interference have
been sufficiently suppressed before activating
the echo stretch feature.
Note 2: Echo stretch is not available on the
ranges between 0.125 and 0.75 nautical miles.
1.23 Watchman
The watchman function periodically transmits
the radar for about one minute to check for
targets in a guard zone. If it finds change in the
zone from the previous transmission it sounds
the audible alarm, cancels the watchman
function and transmits the radar continuously.
This feature is useful when you do not need to
observe the radar continuously but want to be
alerted to radar targets in a specific area,
namely, the guard zone. When the radar starts
transmitting, the buzzer sounds to alert the
operator
St-by
5, 10 or
20 min
Tx
1 min
Tx
1 min
St-by
5, 10 or
20 min
Watchman
starts. * Timer appears and countdowns
time to Tx when 1:00 remains
in ST-BY.
* *
Figure 1-22 How watchman works
Turning watchman on/off
1. Set a guard zone.
2. Press the [MENU] key.
3. Select WATCHMAN.
4. Select transmitting interval, or turn
watchman off as appropriate.
5. Press the [MENU] key.
"WATCHMAN" appears at the top left corner on
the screen when the watchman function ison.
Note: If no guard zone is set, the buzzer sounds
when the radar starts transmitting to alert the
operator.
Canceling watchman
Press any key at any time. If done while
transmitting, watchman is disabled and the
normal display appears. In stand-by, the timer
appears and counts down from one minute, and
then the radar goes into stand-by.