8. MULTI BEAM SONAR DFF-3D
8-11
8.5.6 How to apply correction to the speed of sound
Even though the sea bottom is flat, the left or right edge, up or down may be distorted.
To compensate for this problem, adjust the speed of sound.
Manual correction
1. Select [Settings] on the home screen.
2. Select [Multibeam Sonar] - [Cross Section].
3. Select [Sound Speed Correction], then enter a correction. The setting range is
-200 to +200.
4. Select [Close] to close the menu.
Automatic correction
1. Select [Settings] on the home screen.
2. Select [Multibeam Sonar] - [Cross Section].
3. Select [Temp.-based Correction], then select [ON].
Select [OFF] to remove the correction.
4. Select [Close] to close the menu.
8.5.7 How to show or hide the scale box
The scale box, shown at the bottom-left corner on the display, shows depth and TX
frequency. You can show the box as follows.
1. Tap the cross section display to show the pop-up menu.
2. Select [Scale Box] to show the scale box.
8.5.8 Availability of points and event marks registration, and go to a
point
For how to register points and event marks, see section 4.2.
The table below shows function availability according to latitude/longitude, heading
data presence or absence. If there is no latitude/longitude data, none of the functions
below are available.
For a multi function display, input PGN data. The PGN data available is as shown be-
low.
Latitude/longitude data
• 129025 Position, Rapid Update
• 129029 GNNS Position Data
Heading data
• 127250 Vessel Heading
• 130577 Direction Data