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114
Reference section 7 — Echo sounding
The picture menu
Northstar 972
The picture menu
You can adjust the appearance of echoes in
five different ways:
•
gain (for high intensity echoes)
•
clutter (for low intensity echoes)
•
noise limiter (for interference)
•
hue (to choose colors and white level)
•
signal level (to remove weak echoes)
Gain and clutter changes are applied only
to new echoes as they appear on the right
side of the screen — earlier echoes are not
affected.
Adjusting the gain (strong echoes)
The
gain
setting selects the echo strengths
that will be displayed using the
topmost
color in the color bar at the left edge of the
screen (the
strongest
echoes).
Any echoes stronger than this selection
will use the same color and no detail can
be distinguished. The gain is usually set so
that strong seabed echoes are displayed in
brown, the strongest level.
The gain can be also be set automatically
by pressing
Auto
. This provides an excel-
lent picture under most conditions, and
allows the sounder to reliably detect the
seabed depth.
Gain is normally adjusted together with
clutter
, as described on the next page.
To adjust the gain:
1. At the
Echo Sounder
screen, press
Picture
.
2. Press
Gain
.
3. Press the cursor pad up or down to adjust the
gain, or use the keypad to manually enter the
desired gain value. The available settings
range from zero (minimum) to 75 (maximum).
4. Press
Return
to go back to the
Echo
Sounder
screen.
Adjusting the clutter (weak echoes)
The
clutter
setting selects the echo strength
that will be displayed using the
bottom
colors of the color bar (the
weaker
echoes).
Any echoes weaker than this selection are
not displayed. If you select a clutter value
of
5
, for example, all weak and moderate
echoes are suppressed. You might choose
this setting to eliminate high levels of
background noise and echoes from turbu-
lence or plankton.
A setting of
0
allows all echoes to be
displayed.
To adjust the clutter:
1. At the
Echo Sounder
screen, press
Picture
.
Содержание 972
Страница 1: ...Northstar 972 Quickstart Guide and Reference Manual Revision B ...
Страница 12: ...8 Getting Started Purchasing charts Northstar 972 ...
Страница 19: ...15 Displaying the chart screen Quickstart Guide Revision B Chart screen ...
Страница 30: ...26 SAVE and Man Overboard MOB Northstar 972 ...
Страница 44: ...40 Reference section 1 Using the Chart Screen Using the distance and bearing calculator Northstar 972 ...
Страница 54: ...50 Reference section 3 Position coordinates Using Phantom Loran Northstar 972 ...
Страница 88: ...84 Reference section 5 Creating waypoints and routes Transferring waypoints to and from a PC Northstar 972 ...
Страница 90: ...86 Reference section 6 Radar Transferring waypoints to and from a PC Northstar 972 ...
Страница 106: ...102 Reference section 7 Echo sounding MARPA targets Northstar 972 ...
Страница 130: ...126 Reference section 7 Echo sounding Troubleshooting the echo sounder Northstar 972 ...
Страница 131: ...127 Reference Manual Revision B Reference section 8 Video Video sources 128 Displaying video 128 ...
Страница 134: ...130 Reference section 8 Video Displaying video Northstar 972 ...
Страница 135: ...131 Reference Manual Revision B Reference section 9 Alarms and TideTrack Alarms 132 TideTrack 137 ...
Страница 145: ...141 Reference Manual Revision B Reference section 10 Networking General information 142 Restrictions 142 ...
Страница 148: ...144 Reference section 10 Networking Restrictions Northstar 972 ...
Страница 158: ...154 Reference section 11 Setup Changing the time zone Northstar 972 ...
Страница 164: ...160 Reference section 11 Appendix A Datum list Changing the time zone Northstar 972 ...
Страница 168: ...164 Northstar 972 Notes ...
Страница 169: ...Notes 165 Operator s Manual Revision B ...
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