NorthStar Navigation Echo Sounder NorthStar 491 - Manual (Page 56)

Page 52 491 Echo Sounder Operations Manual
Viewing past echoes using SoundTrac
On the SOUNDTRAC screen, you can use Northstar’s exclusive
SoundTrac feature to look back and examine past echo data.
To enable SoundTrac, at the ECHO screen, press the CURSOR
PAD to the left. A dashed vertical line—called the position
marker—is now displayed.
To move back to echoes that were displayed within the past
few minutes, continue pressing and holding the CURSOR PAD
to the left.
As you move the position marker with the CURSOR PAD , the
marker speed accelerates to quickly scroll to the desired location.
SoundTrac screen
The lat/lon of the position marker is displayed at the bottom of
the picture, along with the time elapsed since the ping, and the
distance and bearing from your present position to the marker
(assuming the navigator is providing position data.) As you
move the position marker left and right, these coordinates
change accordingly.
NOTE:
When you use the position marker on a split screen (showing either
two frequencies, or zoom mode), each half of the screen has a posi-
tion marker. Both markers designate the same physical location.
Echoes from at least
the past three minutes
are available,
depending on the
depth of the water and
the advance speed
you’ve set.