Ship origin / Ship dimensions
When you have several different sensors and transducers on your vessel, and you wish each of them to provide accurate data,
you need to know their relative physical positions. To do this, you must establish one or more common reference points. This reference point is also used to position the sonar echoes relative to the ship symbol on the display presentation.
Use the Ship page to define a specific reference point (Ship Origin or origo) for the various sensors connected to the SN90 system. Do this as accurately as possible. This information is used to create a new origin in the vessel coordinate system.
Transducer
When the installation trunk is mounted, it may not be positioned with the mounting holes perfectly aligned to the centre line
of the vessel. When the hull unit is placed on the trunk, the "forward" mark on the transducer shaft sleeve - and thus also "forward" on
the transducer - may not point forward at all, but several degrees off the centre line. To obtain accurate echo presentations, this misalignment must be adjusted by changing the installation parameters.
NoteProviding the correct value for this rotation is crucial for the sonar performance. An inaccurate or incorrect value will cause the sonar echoes to be presented at the wrong bearing.
Use the Transducer page to define the physical location of the transducer in the vessel coordinate system, as well as the installation angles
(rotation). Do this as accurately as possible.
Motion sensor
The physical rotation of the motion reference unit (MRU) relative to the transducer is required to allow the SN90 system to adjust for roll and pitch as accurately as possible.
NoteCorrect values for motion sensor rotation are critical for the sonar performance.
Use the MRU (Motion Reference Unit) page to insert the physical location and rotation of the motion reference sensor (MRU) with reference
to the vessel coordinate system.