Positioning Sensor Operational Features

Positioning sensor data is recalculated by ECDIS taking into account the receiver offset relative to the vessel’s CCRP, and is displayed in the **Navigational Panel** and the **Log book**.

The vessel’s course vector is constructed from the positioning sensor data. For vector display settings, see the **Vectors and Trajectory** section. The course vector is constructed from the CCRP set in vessel dimensions.

If Differential receiver is enabled in the GNSS receiver settings, but the differential signal receiver is absent — ECDIS will generate a Differential signal lost warning (see table). The coordinate, COG, and SOG fields on the navigational panel will be highlighted in yellow.

Navigation Panel

No.	Field	Description
1	Coordinates	Coordinates received from the GNSS receiver. Coordinate system WGS 84. Received from sentences: `$--RMC`, `$--GLL`, `$--GNS`
	POS	Navigation parameter type — positioning
	GLONASS	Name of the sensor providing the data
	Diff	Sensor operating mode indicator
2	Date/Time	Ship date and ship time, adjusted for the time zone. Received from sentences: `$--RMC`, `$--ZDA`
3	RMS	Root mean square error of position determination. Received from sentence: `$--GSA`.

Important

When switching to dead reckoning mode, it is recommended to calculate RMS and enter it manually after each manual observation


4	Course over ground	Course over ground received from the GNSS receiver. Received from sentences: `$--RMC`, `$--VTG`, `$--GNS`
	COG	Navigation parameter name
	GLONASS	Name of the sensor providing the data
5	Speed over ground	Speed over ground received from the GNSS receiver. Received from sentences: `$--RMC`, `$--VTG`, `$--GNS`
	SOG	Navigation parameter name
	GLONASS	Name of the sensor providing the data

Position Discrepancy

When two or more position sensors are connected to ECDIS, the discrepancy between the Primary and Secondary sensors will be calculated.

Misclousure POS

No.	Element	Description
1		Primary position sensor with priority 0
2		Secondary position sensor with priority 1
3		Secondary position sensor coordinates
4	Discrepancy	Direction and distance between Primary and Secondary positions
5	DR misclousure	Display Secondary position on the ENC. Hide Secondary position — press again

Misclousure POS ENC

No.	Element	Description
1	Primary position	Based on data from Position sensor with priority 0
2	Secondary position	Based on data from Position sensor with priority 1

Position Sensor Warnings

Text	Category	Condition
Position (COG/SOG) error: <sensor name>	Warning	When data from the sensor stops being received according to the configurable timeout.
HDOP exceeded: <sensor name>	Caution	When the HDOP (Horizontal Dilution of Precision) parameter value is greater than 4. Operates only when the GNSS receiver transmits `$--GSA`, `$--GNS` messages.
No GNSS fix: <sensor name>	Warning	Mode indicator in the message has value N (No fix) for packets: `$--RMC`, `$--GLL`, `$--GNS`.
Position lost: <sensor name>	Alarm	Positioning system mode indicator has value E in messages: `$--RMC`, `$--GLL`, `$--GNS`, or when unable to obtain latitude/longitude from any packet: `$--RMC`, `$--GLL`, `$--GNS`.
Differential signal lost: <sensor name>	Warning	Positioning system mode indicator transitions from value D to any other value in messages: `$--RMC`, `$--GLL`, `$--GNS`, or when unable to obtain latitude/longitude from any packet: `$--RMC`, `$--GLL`, `$--GNS`.
Differential corrections not applied: <sensor name>	Warning	Age of differential GPS data indicator. GNSS data staleness indicator in differential mode in `$--GGA`, `$--GNS` messages — empty field. If the receiver was previously in differential mode
GNSS data integrity violation: <sensor name>	Warning	If the sentence fails the CRC check.
Coordinate discrepancy	Warning	If data from the `$--DTM` sentence is absent or the `$--DTM` sentence transmits a coordinate system other than WGS 84