System Operation
file (SVP); this function is normally performed in the Bathymetry Data Acquisition
System (e.g. 6042).
The velocity menu item allows the externally measured speed of sound to be en-
tered directly into the 8101 system. The range allowed is from 1350 to 1600 me-
ters per second. If the local sound velocity is not known, a value of 1480 to 1500
for open sea areas and 1425 meters/sec for fresh water is recommended. Figure
3-4 illustrates typical surface sound velocity at different temperatures and salinity.
These curves should be used only as a general guide.
NOTE
If a sound velocity probe is interfaced to the Sonar Processor, the VELOCITY
value will automatically indicate the value from the instrument and cannot be
changed by the operator.
Sound velocity (at surface)
1400
1420
1440
1460
1480
1500
1520
1540
1560
0
5
10
15
20
25
30
35
Temperature (degrees C)
Velocity (m/sec)
0 ppt
5 ppt
10 ppt
15 ppt
20 ppt
25 ppt
30 ppt
35 ppt
Figure 14, Typical Sound Velocity Values
IMPORTANT
A sound velocity value, at the face of the projector, is REQUIRED for best accu-
racy when using the Optional Pitch Stabilized Projector. This may be from an in-
stalled probe, from a remote serial input, or direct operator input. Failure to
provide the correct sound velocity will affect beam steering calculations.
______________________________________________________________________
SeaBat 8101 Operator's Manual
3-8
Version 3.02
