852-GS Ultra-Miniature Imaging Sonar
Doc No: 430-048-0B
Page
29
of
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3.5.7.
Options => Calibrate Compass
RealTime only
Field calibrates the internal compass. To calibrate the compass, the sonar head must be rotated by 360°
(direction is irrelevant). Check “
Calibrate Compass
”, rotate 360° slowly, then uncheck “
Calibrate Compass
” to
store the settings.
3.5.8.
Options => Calibrate Motor
RealTime only
Calibrates the motor and re-aligns the sonar head position relative to the transducer position.
This can be done periodically to remove unwanted drift.
3.5.9.
Options => Local Lat / Compass Declination
RealTime only
The geographical local latitude compensates for drift caused by the Earth's rotation. Use the Local Lat /
Compass Declination window to set the Latitude (0 to 90 for northern latitudes, 0 to -90 for southern latitudes)
and Compass Declination (offset to magnetic north. West is negative, east is positive).
The following website reports declination
https://www.geomag.nrcan.gc.ca/calc/mdcal-en.php
for a given
position.
3.6.
PROFILE
Regardless of the Profile settings below, all data is logged during data recording.
3.6.1.
Profile => Off
Only image data is displayed (i.e. no profile points).
3.6.2.
Profile => Points Only
Only generated profile points are displayed and no image data is visible.
3.6.3.
Profile => Low Mix
Image data is displayed at quarter intensity along with the generated profile points.
