Units; Sound Velocity - Gemini 620pd Profiling Product Manual

Gemini Software Operation
The configuration options allow for the selection and configuration of the profiling
heads. Each head that is part of the system can be configured and the first step is to
select the Sonar ID of the head to be altered. Each head can then be positioned
in relation to where it is within the system (i.e. offsets can be input to compensate
for the profiling heads being positioned either side of a vessel) by choosing the
fore/aft (Fwd(m)) and port/starboard (Stbd(m)) offsets. The depth can also be set
(Depth(m)) and the amount of roll for each individual head. If using a motion
reference unit the position of this can be set by inserting values into the MRU row
of the table.

12.4.2. Units

The Units control selects between Metric or Imperial units. These are then applied to
range lines and any measurements which are taken.

12.4.3. Sound Velocity

The Gemini Profiler can either use a fixed sound velocity (in which case the sound
velocity to be used is entered in the Fixed Value box below the sound velocity
selector), or use a measured sound velocity.
0695-SOM-00001, Issue: 03
Note
The units selection only affects the screen display. Output to the
hydrographic survey package is always in SI units.
Note
The Sound Velocity controls are used to set how the Gemini obtains
the sound velocity at the receiver face. This is critical for producing the
sonar image/profile. Incorrect sound velocity cannot be corrected with
post-processing.
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Gemini Profiling System
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