Northrop Grumman Sperry Marine VisionMaster FT, User Manual

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Radar/Chart Radar User Guide Overview
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Information on Sensor Inputs to the System
The VisionMaster Radar system is Type Approved using 19", 23.1", 25.5"
and 27" displays with X-Band and S-Band top units. To function correctly
the system requires sensor input from external devices. Any limitations
associated with the method of sensor input are stated below.
Compass Input
The approved method of compass input is via an analogue input, either
through a Synchro or Stepper motor interface. If an analogue input is
unavailable then a serial input may be used with data conforming to IEC
61162-2 at 38400 baud rate and a message update rate of approximately
50Hz. If serial input data at 4800 baud rate, or a lower message update
rate is used then the tracking data will be compromised.
The primary compass data should be used in all circumstances. For
example, re-constituting serial data as analogue data via a converter is
inferior to using the serial data direct.
Log Input
The speed log input used must be compliant to IMO resolution A 824(19).
When a ground speed log is in use, true video trails and target tracking
data will be ground stabilised, using both longitudinal and transverse data if
available from the log. However, a ground speed log may have
inaccuracies in deep waters, depending on the actual depth of the sea.
Additionally, if a single axis log is used it will not take into account
transverse effects due to leeway, tides and currents. The magnitude of
these effects will depend on their strength and direction.
When a water speed log is in use true video trails and target tracking data
will be water stabilised, using both longitudinal and transverse data if
available from the log. The accuracy of tracked target trails and vector data
using a single axis log is only degraded when in True trails; in Relative
trails the data is not affected.
Position Input
The EFPS connected to the system must be compliant with IMO resolution
MSC.112(73) and MSC.114(73). However, there are areas of the world
where coverage is limited and these areas may cause inaccuracies on the
tracking and positioning data.