Kongsberg Simrad SN90, Руководство по установке

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Example
If you wish to measure the actual water depth, you will need to know the
vertical distance from the echo sounder transducer to the water line. Since
the vessel’s displacement changes with the amount of cargo, fuel etc, the
physical location of the water line on the hull must either be measured at a
regular basis, or measured with a second sensor.
+Y
-Y
+Z
-Z
+X
-X
(CD010101_300_001)
A
B
C
D
In order to establish
a system to measure
the relative distance
between sensors, a
virtual coordinate system
is established. This
coordinate system uses
three vectors; X, Y and Z.
A
The X-axis is
the longitudinal
direction of the
vessel, and in
parallel with the deck. A positive value for X means that a sensor or a reference
point is located ahead of the origin (D).
B
The Y-axis is the transverse direction of the vessel, and in parallel with the deck.
A positive value for Y means that a sensor or a reference point is located on the
starboard side of the origin (D).
C
The Z-axis is vertical, and in parallel with the mast. A positive value for Z means
that a sensor or a new reference point is located under the origin (D).
D Origin
Coordinate system origin
The origin is the common reference point where all three axis in the vessel coordinate
system meet. All physical locations of the vessel’s sensors (radar and positioning system
antennas, echo sounder and sonar transducers, motion reference units etc) are referenced
to the origin.
In most cases, the location of the vessel’s "official" origin has been defined by the
designer or shipyard. This origin is normally identified with a physical marking, and also
shown on the vessel drawings.
Frequently used locations are:
• Aft immediately over the rudder (frame 0)
• Vessel’s centre of gravity
• The location of the motion reference unit (MRU)
Coordinate system alternative origins
If necessary, other origin locations may be defined for specific products or purposes.
Simrad SN90