Speed log requirement
In order to operate correctly, the SN90 system requires input from a speed log. Unless specified in the contract, a speed log is not a part of the SN90 system delivery. Provided that a speed log sensor is interfaced to the SN90 system, the vessel’s current speed can be presented in the user interface.
Note
Without speed information, the SN90 system will neither be able to present correct navigational information, nor compensate for vessel movements. This lack of compensation will prevent the system from providing correct echo information.
In most cases a suitable sensor is already installed on the vessel. A global positioning system (GPS) with a compatible output format can also be used.