Furuno ARP-17 User Manual
AUTOMATIC TRACKING AID
MODEL
ARP-17
(
C
9-52, Ashihara-cho,
Nishinomiya, Japan
Telephone: 0798-65-2111
Telefax: 0798-65-4200
All rights reserved.
Printed in Japan
Your Local Agent/Dealer
FIRST EDITION : NOV. 1998
E : JUL. 10, 2001
PUB. No. OME-30460
DAMI)
ARP-17
SAFETY INSTRUCTIONS
WARNING
No one navigational aid should be relied
upon for the safety of vessel and crew.
The navigator has the responsibility to
check all aids available to confirm
position. Electronic aids are not
a substitute for basic navigational
principles and common sense.
• This auto plotter automatically tracks an
automatically or manually acquired radar
target and calculates its course and
speed, indicating them by a vector. Since
the data generated by the auto plotter
are based on what radar targets are
selected, the radar must always be
optimally tuned for use with the auto
plotter, to ensure required targets will not
be lost or unwanted targets such as sea
returns and noise will not be acquired
and tracked.
• A target does not always mean a landmass, reef, ships or other surface vessels
but can imply returns from sea surface
and clutter. As the level of clutter changes
with environment, the operator should
properly adjust the A/C SEA, A/C RAIN
and GAIN controls to be sure target
echoes are not eliminated from the
radar screen.
CAUTION
The plotting accuracy and response of
this auto plotter meets IMO standards.
Tracking accuracy is affected by the
following:
• Tracking accuracy is affected by course
change. One to two minutes is required to
restore vectors to full accuracy after an
abrupt course change. (The actual
amount depends on gyrocompass
specifications.)
• The amount of tracking delay is inversely
proportional to the relative speed of the
target. Delay is on the order of 15-30
seconds for high relative speed; 30-60
seconds for low relative speed.
Display accuracy is affected by the
following:
• Echo intensity
• Radar transmission pulsewidth
• Radar bearing error
• Gyrocompass error
• Course change (own ship or target)
i
TABLE OF CONTENTS
FOREWORD .................................................................................................................. iii
OPERATIONAL OVERVIEW
1. Introduction ...................................................................................................................1
2. Criteria of Tracking........................................................................................................1
3. Controls, Menu Description ..........................................................................................3
4. Activating, Deactivating the ATA ...................................................................................5
5. Entering Own Ship’s Speed..........................................................................................5
6. Acquiring T argets ..........................................................................................................6
7.Terminating Tracking of T argets.....................................................................................8
8. Vectors ..........................................................................................................................8
9. Displaying Target Data..................................................................................................8
10. Past Position Display ..................................................................................................9
11. Set and Drift ................................................................................................................9
12. Alarms.......................................................................................................................10
13. Track Test (Simulation Display).................................................................................11
14. Diagnostic Sequence................................................................................................12
15. Outputting Target Data..............................................................................................13
SPECIFICATIONS ..................................................................................................SP-1
INDEX
ii
FOREWORD
A Word to FURUNO ARP-17 Owners
FURUNO Electric Company thanks you for considering and purchasing the FURUNO Automatic Tracking Aid (ATA) ARP-17. We are confident you will discover why FURUNO has become synonymous with quality and reliability.
For nearly 50 years FURUNO Electric Company has enjoyed an enviable reputation for efficient and dependable marine electronics equipment. This dedication to excellence is furthered by our extensive global network of agents and dealers.
Y our unit is designed and manufactured to meet the rigorous demands of the marine environment. However, no machine can perform to the utmost of its ability unless properly operated
and maintained. Please carefully read and follow the recommended procedures for operation
and maintenance.
We would appreciate hearing from you, the end-user, about whether we are achieving our
purposes.
Thank you for considering and purchasing FURUNO.
Features
The ATA ARP-17 is an optional circuit board which is accommodated in the display unit of the
FR-1500 MARK-3 Series Radars and the FR-1710/1725/1760DS radars.
The ATA permits manual acquisition and automatic tracking of up to 10 radar targets. An
internal microprocessor calculates target data such as speeds and courses and displays the
results in alphanumeric and by vectors.
When the ARP-17 is installed (whether or not in use), EP A (manual acquisition, manual tracking with 10 selected symbols) is disabled.
• Manual acquisition of up to 10 targets between 0.2 and 32 nm
• Automatic tracking of up to 10 manually acquired targets between 0.1 and 32 nm
• Vector length adjustable and vector reference in true or relative
• Motion trend displayed within 1 min., full accuracy within 3 min. after acquisition
• Past position display shows last ten positions.
• Visual and audible alarms against targets violating CPA/TCPA limits; visual alarms against
lost targets.
iii
OPERATIONAL OVER VIEW
1. Introduction
The FR-1500 MARK-3 series radar and the
FR-1710/1725/1760DS can accommodate an
optional ATA (Automatic Tracking Aid) module complying with IMO MSC.64(67) Annex
4 and IEC 60872-2. With the optional A T A circuit board (ARP-17) Fitted in the display unit,
the radar will automatically acquire 10 targets
coming into the acquisition area. Once a target is acquired automatically or manually it is
automatically tracked within 0.1 to 32 nm,
whether inside or outside the acquisition area.
2. Criteria of Tracking
A target measuring 800 m or more in the radial or circumferential direction is regarded
as a landmass and not acquired or tracked.
Echoes smaller than 800 m are regarded as
targets to be tracked.
The FURUNO ARPA ATA video processor
detects targets in midst of noise and discriminates radar echoes on the basis of their size.
Target whose echo measurements are
greater than those of the largest ship in range
or tangential extent are usually land and are
displayed only as normal radar video. All
smaller ship-sized echoes which are less than
this dimension are further analyzed and regarded as ships and displayed as small
circles superimposed over the video echo.
When a target is first displayed, it is shown
as having zero true speed but develops a
course vector as more information is collected. In accordance with the International
Marine Organization Automatic Radar Plotting Aid (IMO ARPA) requirements, an indication of the motion trend should be available
within 20 scans of antenna and full vector
accuracy within 60 scans. The FURUNO
ARPAs/ATAs comply with these requirements.
Acquisition and tracking
A target which is hit by 5 consecutive radar
pulses is detected as a radar echo.
Auto acquisition is not defined in paints but
in time, which should be less than 3 s of initial stage.
Manual acquisition is done by designating a
detected echo with the trackball. Automatic
acquisition is done in the acquisition areas
when a target is detected 5-7 times continuously depending upon the congestion. Tracking is achieved when the target is clearly
distinguishable on the display for 5 consecutive or alternate paints out of 10 consecutive
scans whether acquired automatically or
manually.
Targets not detected in 5 consecutive scans
become “lost targets.”
Quantization
The entire picture is converted to a digital
from called “Quantified Video.” A sweep range
is divided into small segments and each
range element is “1” if there is radar echo
return above a threshold level, or “0” if there
is no return.
The digital radar signal is then analyzed by a
ship-sized echo discriminator. As the antenna
scans, if there are 5 consecutive radar pulses
with 1’s indicating an echo presence at the
exact same range, a target “start” is initiated.
Since receiver noise is random, it is not three
bang correlated, and it is filtered out and not
classified as an echo.
The same is true of radar interference. Electronic circuits track both the closet and most
distant edges of the echo. At the end of the
scanning of the echo, the discriminator indicates the measured maximum range extent
and total angular extent subtended by the
echo. If the echo is larger than a ship-sized
echo in range extent and/or angular width,
adjusted as a function of range, it is declared
1
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