121
Reference section 7 — Echo sounding
Echo sounding alarms
Reference Manual Revision B
Echo sounding alarms
The echo sounder’s alarms work just like
all other alarms: they are displayed as a
flashing alarm icon on the screen, with
details shown on the
Alarms
screen
accessed with the
STAR
key. (See
Alarms,
starting on page 132.)
To alert you automatically in situations
related to echo sounding, you can set three
types of alarms:
•
fish alarm
•
seabed bottom alarm
•
temperature alarm
Setting the fish alarm
When the fish alarm is on, an alarm sounds
if an echo returns from either inside or
outside specific upper and lower limits
you’ve set.
You can selectively limit the size of the fish
you want to be notified about by adjusting
the alarm’s echo strength level. Using this
feature, you’ll only be alerted to the
presence of fish that meet your minimum
size requirements.
You may further narrow your fish alarms
to notify you of the presence of fish within
(or outside) a certain depth range. Only
those fish that are detected inside (or
outside) of that range will trigger the
alarm. Green markers are displayed to
indicate the range.
When fish are detected, the alert tone
sounds and the flashing
FISH
alarm icon is
displayed. This message clears automati-
cally after 20 seconds and the alarm is
rearmed.
To access the fish alarm settings:
1. At the
Echo Sounder
screen, press
More
.
2. Press
Alarms
.
3. Press
Fish alarm
.
Setting the alarm’s echo strength level
To set the fish alarm’s minimum
echo-strength level:
1. At the
fish alarm
window, press
Level
.
2. Press the cursor pad up or down to set the
echo strength level from 1 to 15.
Echoes that are stronger than the selected
level will cause an alarm.
Setting the upper and lower marker depths
The fish alarm will sound only when there
are echoes inside (or optionally, outside)
the upper and lower markers. These
markers are displayed on the
Echo Sounder
screen.
Summary of Contents for 972
Page 1: ...Northstar 972 Quickstart Guide and Reference Manual Revision B ...
Page 12: ...8 Getting Started Purchasing charts Northstar 972 ...
Page 19: ...15 Displaying the chart screen Quickstart Guide Revision B Chart screen ...
Page 30: ...26 SAVE and Man Overboard MOB Northstar 972 ...
Page 54: ...50 Reference section 3 Position coordinates Using Phantom Loran Northstar 972 ...
Page 90: ...86 Reference section 6 Radar Transferring waypoints to and from a PC Northstar 972 ...
Page 106: ...102 Reference section 7 Echo sounding MARPA targets Northstar 972 ...
Page 130: ...126 Reference section 7 Echo sounding Troubleshooting the echo sounder Northstar 972 ...
Page 134: ...130 Reference section 8 Video Displaying video Northstar 972 ...
Page 148: ...144 Reference section 10 Networking Restrictions Northstar 972 ...
Page 158: ...154 Reference section 11 Setup Changing the time zone Northstar 972 ...
Page 164: ...160 Reference section 11 Appendix A Datum list Changing the time zone Northstar 972 ...
Page 168: ...164 Northstar 972 Notes ...
Page 169: ...Notes 165 Operator s Manual Revision B ...
Page 170: ...166 Northstar 972 Notes ...
Page 171: ...Notes 167 Operator s Manual Revision B ...
Page 172: ...168 Northstar 972 Notes ...
Page 173: ...Notes 169 Operator s Manual Revision B ...
Page 174: ...170 Northstar 972 Notes ...
Page 175: ...Notes 171 Operator s Manual Revision B ...
Page 176: ...172 Northstar 972 Notes ...
Page 177: ...Notes 173 Operator s Manual Revision B ...
Page 178: ...174 Northstar 972 Notes ...
Page 179: ...Notes 175 Operator s Manual Revision B ...
Page 180: ...176 Northstar 972 Notes ...
Page 181: ...Notes 177 Operator s Manual Revision B ...
Page 182: ...178 Northstar 972 Notes ...
Page 183: ...Notes 179 Operator s Manual Revision B ...
Page 184: ...180 Northstar 972 Notes ...