Prerequisites
Neither tools nor instruments are required.
The relevant offset values can normally be taken from the vessel drawings.
Context
The SU90 system is provided with a built-in motion sensor to provide electronic stabilization of the sonar beams. It is placed inside the Motor Control Unit. The motion sensor measures the roll and pitch movements of the vessel.
NoteIf you want to use the built-in motion sensor, you do not need to enter any offset values.
If the hull unit has been installed with the Motor Control Unit pointing straight aft, you do not need to enter any rotation
values. However, if the unit faces in any other direction you must compensate for this by entering the relevant value for Rotation Around Z.
For improved operational accuracy, an external motion reference unit (MRU) may be used.
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Offsets: The offset values specify the physical location of the motion reference unit relative to the reference point (origin). The relevant offset values can normally be taken from the vessel drawings. |
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Rotation: The values for rotation around the X, Y and Z axis are used to compensate for any misalignments made during the physical installation
of the motion reference unit. Such misalignments occur if the sensor is not placed in parallel with the vessel’s horizontal and/or vertical planes. We strongly recommend that you install your motion reference unit so that all rotation angles can be set to 0 (zero). |
The required accuracy of the offset and rotation angles depends on the accuracy requirements for the echo data.
TipThe motion sensor offset values are not important for sonar operation. Correct values for motion sensor rotation are important for roll and pitch compensation.
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Rotation around the x-axis: In the positive horizontal direction (forward), a positive rotation is clockwise. |
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B |
Rotation around the y-axis: In the positive horizontal direction (starboard), a positive rotation is clockwise. |
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C |
Rotation around the z-axis: In the positive vertical direction (down), a positive rotation is clockwise. |
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D |
Reference point (Ship Origin) |