Inserting the installation parameters for the transducer
The physical location and the installation angles of the transducer are critical for the echo data accuracy. Incorrect angles will greatly reduce the data accuracy.
Prerequisites
For accurate location of the transducer, you need the detailed vessel drawings. You also need the alignment angle that was recorded when the hull unit was installed. Neither tools nor instruments are required. The ME70 system is turned on and operates normally.
Note
Determining the relative positions and orientations of the sensors and each transducer with high accuracy is important. This requires professional land surveying done by qualified and trained surveyors using proven survey equipment and methods. We recommend that you use third-party consultants with well proven experience with vessel dimensional control. The information provided by the dimensional survey is entered into the ME70 software as installation parameters.
Context
The physical location and the installation angles of the transducer are critical for the echo data accuracy.
Use the centre of the transducer face as reference, and define the offset values related to the Ship Origin. The installation angles relevant for the transducer must also be defined. These values were recorded during the installation, and they define the direction of the transducer face.
Note
The required accuracy of the offset and rotation angles depends on the accuracy requirements for the echo data. It is very important that the transducer installation angles are measured and recorded accurately during the installation. These angles must be accurately defined in the operating software. Incorrect angles will greatly reduce the data accuracy.
Procedure
1 Open the Setup menu.
2 On the Setup menu, select Installation.
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Observe that the Installation dialog box opens. This dialog box contains a number of pages selected from the menu on the left side.
3 On the left side of the Installation dialog box, select the small white triangle next to Installation Parameters.
Observe that a menu opens with access to all the individual pages.
4 Select Transducer to open the page.
5 Insert the relevant offset values.
a X Offset: Insert the horizontal distance on the x-axis (fore-and-aft direction) between the transducer and the Ship Origin.
b Y Offset: Insert the horizontal distance on the y-axis (athwartship direction) between the transducer and the Ship Origin.
c Z Offset: Insert the vertical distance on the Z axis between the transducer and the Ship Origin.
To do this you will need the ship drawings.
6 Obtain the alignment angle from the dimensional survey report.
a Rotation Around X: Specify an angle (in degrees) to compensate for any deviation from the X axis (fore-and-aft direction) in the vessel coordinate system. If the transducer is properly installed without unintentional skew, this angle can be set to 0 degrees.
b Rotation Around Y: Specify an angle (in degrees) to compensate for any deviation from the Y axis (athwartship direction) in the vessel coordinate system. This angle is normally 0 degrees.
c Rotation Around Z: Specify an angle (in degrees) to compensate for any deviation from the Z axis (vertical direction) in the vessel coordinate system. This is the alignment angle. This angle is normally 0 degrees.
Do this as accurately as possible.
7 In Mounting define how the transducer is mounted on the vessel.
•  Hull-Mounted: The transducer is mounted on the vessel’s hull.
•  Drop Keel: The transducer is mounted on the drop keel of the vessel.
Note
If you select Drop Keel and the transducer is pointing down, depth calculations will automatically account for the drop keel position.
8 At the bottom of the page, select Apply to save your settings.
9 Continue your work in the Installation dialog box, or select OK to close it.