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Sarpa/ais, Target association (fusion), Data display – Furuno FAR-2157 User Manual

Page 6: Symbols for ais, Symbols for arpa

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Past

positions

Vector shows trend

of movement.

Initial stage

Steady tracking

CPA alarm

Lost target

(Flashing)

Past Position Display

The ARPA displays equally time-spaced dots

marking the past positions of any targets being

tracked. A new dot is added during preset time

intervals until the preset number is reached. AIS

also displays past position dots.

s

ARPA/AIS

Target automatically

acquired

AIS-equipped target

selected for data reading

Water temp,

Depth,

Wind

DATA Cell 1
AIS information

DATA Cell 2
Tracking data

DATA Cell 3
Tracking data

Target Association (Fusion)

An AIS-equipped ship may be shown on the display by both AIS and

ARPA symbols. This happens because the AIS position is measured

by a GPS navigator in L/L while the ARPA target blip and data are

measured by range and bearing from own ship. When the symbols are

within an operator-set criteria, the ARPA symbol is merged into the AIS

symbol. The criteria is determined by the differences in range, bearing,

course, speed, etc.

Data Display

A variety of navigational information which

is vital for fishing vessels, including own

ship status, radar plotting data, wind,

water temperature and information from

other shipborne sensors can be displayed

in the data cells on the right hand side of

the screen. The FAR-2157 and 2167DS

radar have a unique zoom function which

enlarges a part of the radar image twice or

three times in size.

Symbols for AIS

Information to be presented

Static Data

MMSI (Maritime Mobile Service Identity)

IMO number (Where available)

Call sign & name

Length and beam

Type of ship

Location of position-fixing antenna on the ship

Voyage related data

Ship’s draft

Hazardous cargo (type)

Destination and ETA

(at master's discretion)

Short safety-related messages

Free messages

Information to be exchanged

Dynamic data

Ship’s position with accuracy

indication and integrity status

Coordinated universal time (UTC)

Course over ground (COG)

Speed over ground (SOG)

Heading

Navigation status (manual input)

Rate of turn (where available)

Update rates Dependent on speed

and course alternation (2 s – 3 min)

*1 Vector shows STW

(speed thru water) and

CSE (course) when water

tracking mode is selected

at the radar. the length

of the vector changes

according to target's

speed.

Past positions

Turning direction

(ROT indicator)

Sleeping AIS Target

SOG (Speed over Ground) and

COG (Course over Ground) vector *1

Heading line *2

Selected Target

Lost Target

Dangerous Target

*2 If there is no heading

data, the line points in

direction of COG.

Bearing from own ship to target in R (Relative) or T (True)

Range from own ship to target

Course Over Ground (COG)

Speed Over Ground (SOG)

Closest Point of Approach of target to own ship (CPA)

Time to CPA (TCPA)

Bow Crossing Range of target (BCR)

Bow Crossing Time of target (BCT)

Selecting the shape of ARPA symbols

After tracking a target, you can select and change the ARPA symbol shape by

placing the cursor on the symbol and hitting the “TARGET DATA” key.

It is useful to change the ARPA symbol to distinguish vessels and identify groups

of related targets.

The ARPA symbols are selectable from 10 shapes.

Zoom

AIS

Information

Own ship data cell

Symbols for ARPA