Kongsberg Simrad MF90, Installation Manual

Page: 274 / 426

272
476671/B
Related topics
Setting to work, page 186
Inserting the installation parameters, page 259
Inserting the installation parameters for the motion reference unit (MRU), page 266
Adjusting the stabilization offsets for the external motion sensor, page 272
Adjusting the stabilization offsets for the external motion
sensor
The MF90 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. For improved operational
accuracy, an external motion reference unit (MRU) can be used. It is very important that the
motion sensor is set correctly with stabilization offset values that are adapted to the physical
installation angles of the hull unit. To align an external motion sensor to the internal sensor,
you may need to adjust the stabilization offset values. This task is only applicable is you are
using an external motion reference unit on your MF90 system.
Prerequisites
Note
Before you do this task you must adjust the installation offset of the motion sensor.
The MF90 system hardware units are installed as specified in this manual.
• The external motion sensor is connected to the MF90 system.
• The MF90 system is turned on and operates normally.
• The vessel is berthed.
Note
We recommend that you do this task in calm sea without any vessel movements.
Context
It is very important that the motion sensor is set correctly with stabilization offset values
that are adapted to the physical installation angles of the hull unit. Even a small offset error
can give you very inccurate readings. In many cases a suitable motion sensor is already
installed. This sensor may be mounted anywhere on the vessel. Because of this, the risk of
stabilization offset misalignment is present.
The two screen captures below illustrate how the MF90 system can provide inaccurate data
if the stabilization offset is misaligned. In both examples, the tilt is set to approximately 24
degrees, and you are looking at the echoes from a flat bottom at a very short range. The
Simrad MF90 Installation Manual