JLN-550 Doppler Sonar is designed to provide ship speed information with higher stability in the dual frequency modes; one using a lower ultrasonic frequency that is adequate to measure the ship’s speed against the ground  up  to  larger  depths  and  the  other  using  a  higher  ultrasonic frequency that allows the ship’s speed against the water to be measured even in water with tiny bubbles.

The transducer is designed for dual-frequency transmission, but its size is smaller than the conventional models.

Ship speed measurement is insensible to bubbles generated in high-speed navigation, ensuring stable speed display.

The transducer is substantially downsized, allowing it to be installed on the bow side that is little affected by bubbles.

An underwater-mateable connector is adopted for the transducer, so that a transducer can be replaced at a quay even in case of its failure.

The  equipment  is  provided  with  an  additional  function  of  indicating  the  ship’s  fore  and  aft speeds and port and starboard speeds by entering GPS information.

The  ship’s  port  and  starboard  speeds  at  its  arbitrary  position  can  be  indicated   by  entering ROT information.

An optimal Doppler sonar system can be configured by combining a variety of options. On-line maintenance (option) allows any failure to be detected during navigation.


Price: Contact


Price: Contact


Operating system 2- axis 4-beam pulse Doppler sonar or ROT-combined 3-axis 4-beam pulse Doppler sonar (ROT:option)
Operating frequencies 240kHz (BT : for speed against the ground)
2MHz (WT : for speed against the water)
Speed range BT Fore/Aft : -10.00 to +40.00 kts
Port/Stb.: -9.99 to +9.99 kts
Stern P/S : 9.99 to +9.99 kts (with optional ROT)
WT Fore/Aft : -10.00 to +40.00 kts
Distance run range 0 to 99999.99nm
Depth range BT : 2 to 250m (below hull bottom)depending upon sea bottom conditions
WT : 3m or more (below hull bottom)
Speed measuring accuracy ±1% or 0.1 kts whichever is greater
Total distance run accuracy ±1% or 0.1 nm whichever is greater
Ship speed indication XX.XX 4-digit indicator (in kts or m/s)(P/S:3-digit)
Analog indication (in kts)
IEC61162-1 inputs
ROT (Stern P/S speed)**ROT (excl.GPROT)
GYRO (GPS ship speed)HDT,HDG
Data outputs IEC61162-1 : 2000 outputs : 5 circuits VBW,VLW,DPT,DBT
DC voltage output : 2 circuits (for analog indicator)
Opto coupler signal : 8 circuits (200 pulses/nm)
Relay closure signal : 1 circuit (200 pulses/nm)
Relay closure signal : 1 circuit (Power fail alarm)
Power supply 100 / 110 / 115 / 220 / 230VAC
±10%, 50 / 60Hz, single-phase
Power consumption 300VA or less
Operating temperature -15deg.C to +55deg.C

Standard Components

Description Model Quantity Remarks
Main Display NWW-60DB 1 DB:2-axis flush mount type (standard)
DA:2-axis wall mount type
TB:3-axis flush mount type
TA : 3-axis wall mount type
Signal Distributor NQA-3012 1
Signal Processor NJC-24 1 IP55
Transducer NKF-770 1 With underwater-mateable
connector and max.40m cable
Spare Parts 7ZXBS0018 1
Instruction Manual 7ZPBS2802 1 English


Component Model Quantity Remarks
Wing Display NWW-61D 2 D: 2-axis, IP56
T: 3-axis
Remote Display NWW-24 2 max. Analog Flush-mount type
Remote Display NWW-25 1 Analog wall mount type
Remote Display NWW-26 1 Analog Flush-mount type
Distance Counter NWW-7B 1 Flush-mount type
Gyro Sensor NJZ-1080 1 ROT
Operator Unit NWZ-120GA 1 ROT, GA : Wall-mount type
GB : Flush-mount type
Rectifier NBA-3263 1 ROT
Dimmer Unit NCM-227 1 For NWW-60 Main Display
Dimmer Unit NCM-329H 1 For NWW-24 / 25 / 26
Remote Display Unit
Transducer NKF-770W 1 Inner demountable type
Transducer NKF-772 1 Gate valve type