Furuno CI-80 User Manual
DOPPLER SONAR
CURRENT INDICATOR
CI-80
A
(
C
9-52, Ashihara-cho,
Nishinomiya, Japan
Telephone: 0798-65-2111
Telefax: 0798-65-4200
ll rights reserved.
Printed in Japan
Your Local Agent/Dealer
FIRST EDITION : FEB. 1995
F : JAN. 6, 2001
PUB. No. OME-72390
CI-80
DAMI)
SAFETY INSTRUCTIONS
WARNING
ELECTRICAL SHOCK HAZARD
Do not open the equipment.
Only qualified personnel
should work inside the
equipment.
Immediately turn off the power at the
switchboard if water leaks into the
equipment or something is dropped in
the equipment.
Continued use of the equipment can cause
fire or electrical shock. Contact a FURUNO
agent for service.
Do not disassemble or modify the
equipment.
Fire, electrical shock or serious injury can
result.
Do not place liquid-filled containers on
the top of the equipment.
Fire or electrical shock can result if a liquid
spills into the equipment.
Immediately turn off the power at the
switchboard if the equipment is emitting
smoke or fire.
WARNING
Keep heater away from equipment.
A heater can melt the equipment’s power
cord, which can cause fire or electrical
shock.
Use the proper fuse.
Fuse rating is shown on the equipment.
Use of a wrong fuse can result in equipment damage.
Do not operate the equipment with wet
hands.
Electrical shock can result.
CAUTION
A warning label is attached to the
equipment. Do not remove the label.
If the label is missing or damaged,
contact a FURUNO agent or dealer.
WARNING
To avoid electrical shock, do not
remove cover. No user-serviceable
parts inside.
Name: Warning Label (1)
Type: 86-003-1011-0
Code No.: 100-236-230
Continued use of the equipment can cause
fire or electrical shock. Contact a FURUNO
agent for service.
Make sure no rain or water splash leaks
into the equipment.
Fire or electrical shock can result if water
leaks in the equipment.
i
Table of Contents
PRINCIPLE OF MEASUREMENT................................................................................ 1
PRINCIPLE OF MEASUREMENT, FEATURES.................................................................................. 1
TIDE, NAV-TIDE & TIDE DIFFERENTIAL ..........................................................................................4
IMPORTANT NOTICE ON TIDE MEASUREMENTS.......................................................................... 8
Features ............................................................................................................................................10
SYSTEM OVERVIEW..................................................................................................11
Control Description............................................................................................................................ 11
How to Read the Displays................................................................................................................. 13
MAIN MENU DESCRIPTION...................................................................................... 16
DEP Menu.........................................................................................................................................16
ECHO Menu......................................................................................................................................17
TRK Menu .........................................................................................................................................17
MARK Menu......................................................................................................................................18
AVR Menu .........................................................................................................................................18
OPERATION............................................................................................................... 19
Basic Operating Procedure...............................................................................................................19
Setting Tide Measuring Depths on the Echo Display........................................................................ 22
Setting up the Echo Display.............................................................................................................. 23
Setting up the Course Plot Display ...................................................................................................24
Marks ...............................................................................................................................................25
Calculating Trip Distance................................................................................................................... 26
Calibrations (offsets) .........................................................................................................................26
Water Speed Display Setting.............................................................................................................27
Nav Data Setting...............................................................................................................................28
MAINTENANCE & TROUBLESHOOTING................................................................. 29
Preventive Maintenance.................................................................................................................... 29
Troubleshooting.................................................................................................................................30
Self Tests, Demonstration Display..................................................................................................... 31
Self T e st Results................................................................................................................................33
MENU TREE............................................................................................................... 36
SPECIFICATIONS.................................................................................................. SP-1
ii
PRINCIPLE OF MEASUREMENT
PRINCIPLE OF MEASUREMENT, FEATURES
When a moving vessel emits an acoustical pulse into the water
at an angle, a portion of emitted energy is reflected from the
seabed and other microscopic objects in the sound path, such
as plankton or air bubbles. The frequency of the received
signal is shifted from the transmitted frequency in proportion to
relative velocity between the vessel and underwater reflecting
objects. This is called Doppler Effect.
The CI-80 calculates and displays movements of ship and
currents at specific depths by measuring Doppler shifts
obtained from three separate directions.
Planktonic layer
Seabed
Figure 1
Frequency of reflected signal is
shifted in proportion to relative speed
between the vessel and reflecting
objects.
Ship’s Speed (Here, speed is a vector value including velocity and direction.)
Depending on the base of measurement, ship’s speed is
expressed in two ways:
Ground tracking speed: Ship’s speed and course relative to
(Absolute speed) seabed (fixed base)
Water tracking speed: Ship’s speed and course relative to
(Relative speed) water layer just below the vessel
(floating base)
Nav-aided speed: Ship’s speed and course obtained
(Absolute speed) by external navigation equipment
(GPS)
1
GPS satellites
Water tracking speed
Nav-aided speed
(Pseudo ground tracking speed)
Near-surface layer
Tide
Ground tracking speed
Fixed
:Base of measurement
Figure 2
Tide is movement of watermass at a particular depth.
To know absolute tide (speed on ground), the following two
data are required:
1
Ship’s speed and course based on ground
2
Ship’s speed and course based on measuring layer (A)
Absolute tide is, then, given as a difference of these two speed
vectors.
2
Absolute Tide =
1
–
2
Layer (A)
1
Fixed
:Base of
measurement
Figure 3
2
Nav Tide
Nav-Tide is an absolute movement o f watermass at a particular
depth, taking speed information from the external navigator
(GPS) as a pseudo ground tracking speed.
To calculate Nav-tide, the following two data are required:
1
Ship’s speed and course obtained by external navigation
equipment (GPS)
2
Ship’s speed and course based on measuring layer (A)
Nav-tide is, then, given as a difference of these two speed
vectors.
2
Absolute Tide =
GPS satellites
1
–
1
Nav-aided speed
(Pseudo ground tracking speed)
Tide Differential
2
Water tracking
speed
:Base of measurement
Layer (A)
Figure 4
Tide differential is a relative movement of tides at different
depths, layer (A) and layer (B).
To calculate tide differential, the following two data are used:
1
Ship’s speed and course based on layer (A)
2
Ship’s speed and course based on layer (B)
Tide differential between two layers is, then, given as a
difference of these two speed vectors.
3
Tide Difference = 1 - 2 (Movement of layer B based on
layer A)
or
2
- 1 (Movement of layer A based on
=
layer B)
1
Layer (A)
2
Layer (B)
Figure 5
TIDE, NAV-TIDE & TIDE DIFFERENTIAL
Tide (Absolute tide)
Absolute tide can be measured in the ground tracking mode.
10 NM (1 hour trip)
Start of
trip
(Moving at 10 kt on ground)
Layer A
1
(Moving at 3 kt on ground)
2
:Base of measurement
End of
trip
:Base of
measurement
Fixed
Figure 6
Assume that the ship and layer A are moving in the same
direction, and ship’s speeds based on ground (Vg) and on lay er
A (Vwa) are measured as;
Vg = 10 kt (Ship’s speed based on ground)
Vwa = 7 kt (Ship’s speed based on layer A).
4
Nav-Tide (Absolute tide)
Tide Differential
Speed of layer A based on ground (C1) can be calculated as
follows:
C1 = Vg – Vwa
= 10 – 7
= 3 (kt)
Absolute tide can be measured in the nav-aided mode.
Nav-aided ship’s speed (Vn) is equivalent to ship’s ground
tracking speed in the ideal conditions. That is, the nav-tide can
be calculated by simply replacing Vg with Vn in the above
equation.
Tide differential is a relative movement of tides at different
depths.
Start of
trip
Layer A
Layer B
2
(Moving)
(Moving)
2 kt
It can be measured in the ground tracking, water tracking and
nav-aided modes.
10 NM (1 hour trip)
End of
trip
3
:Base of measurement
5 kt
Figure 7
5
Assuming that the ship, layer A and layer B are moving in the
same direction, and ship’s speeds based on layer A (Vwa) and
on layer B (Vwb) are measured as;
Vwa = 8 kt (Ship’s speed based on layer A)
Vwb = 5 kt (Ship’s speed based on layer B)
Tide differential calculations in ground tracking mode
As an absolute ship’s speed (Vg) is available in the ground
tracking mode, tide speeds of layer A (C1) and layer B (C2)
based on ground are calculated as follows:
C1 = Vg - Vwa (Speed of layer A based on ground)
C2 = Vg - Vwb (Speed of layer B based on ground)
Thus, the tide differential (Cd) between layer A and layer B is;
Cd = C2 - C1
= (Vg - Vwb) - (Vg - Vwa)
=Vwa - Vwb
=8 - 5
= 3 (kt)
or
Cd = C1 - C2
= (Vg - Vwa) - (Vg - Vwb)
= Vwb - Vwa
= 5 - 8
= -3 (kt)
In the water tracking mode, watermass just below the
transducer (near-surface layer) is taken as the base of all
measurements (virtual ground). Therefore, the ship and tide
speeds in the water tracking mode are not absolute but relative
to this near-surface layer.
Tide differential based
on layer A
Speed of layer B
viewed from layer
A
Tide differential based
on layer B
Speed of layer A
viewed from layer
B
Vw = 9 kt (Ship’s speed based on near-surface layer)
Vwa = 8 kt (Ship’s speed based on layer A)
Vwb = 5 kt (Ship’s speed based on layer B)
6
Start of
trip
Nearsurface
layer
10 NM (1 hour trip)
21
3
End of
trip
Layer A
Layer B
1 kt
:Base of measurement
Assume that the ship and all measuring layers
are moving in the same direction, but at different
speeds.
2 kt
5 kt
Figure 8
7
[READ THIS FIRST!!]
IMPORTANT NOTICE ON TIDE MEASUREMENTS
(In the nav-aided mode, tide accuracy depends heavily on gyro
accuracy.)
SETTING SHIP’S HEADING
The CI-80 has the nav-aided mode to measure absolute tides
even in deep waters where ground tracking is unattainable. To
achieve reliable measurements, however, you must supply
accurate heading (gyro) information and ship’s position (or
speed/course) data to the CI-80.
If you are going to use the nav-aided mode, set the reading of
the AD converter (gyro interface) exactly w i th that of the master
gyrocompass.
Procedure
Master
Gyrocompass
1. Confirm that the gyrocompass has settled and all the
necessary compensations (latitude compensation, weather
compensation, etc.) are made correctly.
2. Operate the AD converter to obtain the same reading as
you read on the master gyrocompass. (Do not make
adjustment while the ship is turning.)
AD Converter
(Gyro Interface)
Figure 9
If the gyro reading is accurate, the CI-80 should provide
accurate tide information. If the gyro data contains some error,
however, you may see the following symptoms.
• Set/drift information on the nav-aided mode differs from that
on the ground-tracking mode.
• Tide/tide differential information on the nav-aided mode
differs from that on the ground-tracking mode.
8
20
10
0
10
20
20
10
0
10
20
1°
0.2
kt
GT Mode
-3°
0.5
kt
NAV Mode
GT Mode NAV Mode
Figure 10
9
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