Dual Axis Doppler Speed Log

Marinelite dual axis doppler speed log-HDL9000

 

What is a Dual Axis Doppler Speed Log?

Based on the Doppler effect principle, the dual axis doppler speed log emits high-frequency acoustic signals to the seabed or water column, and calculates the ship's speed by analyzing the frequency shift of the reflected signals. Unlike single-axis models that only measure speed along the ship's longitudinal direction (fore-aft), HDL9000 realizes simultaneous measurement of two orthogonal axes: longitudinal speed and transverse speed.

 

Technical Advantages

This dual-dimensional data output provides comprehensive motion state information for the ship, laying a solid foundation for precise navigation and maneuvering.

 

Our dual axis doppler speed log is a highly accurate and reliable instrument that is designed to provide precise measurements of the speed and distance of a vessel. With dual axis technology, this speed log can simultaneously measure the speed of a vessel both along its longitudinal axis and across its transverse axis, giving you a more precise reading of your vessel's speed and direction.

This speed log is durably constructed with high-quality materials and is designed to withstand the harsh marine environment. It is easy to install and operate, making it a valuable tool for navigating in all types of water conditions.

 

Marinelite dual axis doppler speed log-HDL9000 delivers strong anti-interference performance and wide detection range. It can stably work in various water conditions, including shallow water (≥3 meters), deep sea, and turbid water, ensuring continuous and reliable speed data output even in harsh marine environments.

 

Multiple NMEA0183 and pulse outputs

The measured speed data can be seamlessly integrated with ECDIS, autopilot systems, and AIS, enabling the ship's navigation system to make timely and accurate adjustments.

 

 

Technical Specifications

Our dual axis doppler speed log meets international maritime standards and has passed strict marine equipment certification, with key specifications as follows:

1. Basic Performance Parameters

Transceiver Operating Frequency	1 MHz
Number of Beam Channels	2 Channels / 4 Channels (Optional)
Speed Measurement Range	Longitudinal: -40.0 ~ 40.0 knTransverse: -40.0 ~ 40.0 kn
Mileage Measurement Range	Over Water 0.0 ~ 99999.9 nm
Tracking Depth	More than 3m below the keel
Speed accuracy	± 2% or 0.2 kn, whichever is greater
Mileage accuracy	± 2% or 0.2 nm/h, whichever is greater

 

 

2. Display unit

Screen	7-inch LCD 800*480 4.2-inch LCD 720*672 (optional)
Illuminance	600 cd/m²
Visible Distance	Unit indication: 0.85m
System Language	Simplified Chinese/English

 

3.Interface

NMEA 0183	IEC61162-1 Ed5 Input/output 6 units
NMEA 2000	1 (optional)
PPS	2
Speed Analog Current Output	2 (Optional)
Speed Analog Voltage Output	2 (Optional)
Output Sentences	Standard: VBW, VLW Optional: ALF, ALC, ALR, HBT, RMC, GGA, VTG, GLL
Input Sentences	Optional:ACN,RMC,GGA,GLL,VTG,HBT

 

 

4. Power Supply

100~240 VAC: 1.8 A1 unit 50/60 Hz

 

 

5.Working Environment

Transducer Unit Ambient Temperature	-5 ℃ ~ +35 ℃
Other Units Ambient Temperature	-15 ℃ ~ +55 ℃
Relative Humidity	93% or +55 ℃
Display Unit Protection Level	IP 22
Transceiver Unit Protection Level	IP 44
Protection Level of Display Unit	IP 67
Protection Level of Distributor Unit	IP 22
Transducer Unit	IP 68
Vibration	IEC 60945 Ed.4

 

FAQ：Dual-Axis Doppler Log

1. How does this Doppler log calculate speed, and is the measurement accurate?
It adopts classic Doppler acoustic principle, emitting high-frequency sound waves to calculate speed through water and over ground by capturing signal frequency shift. With optimized beam design and digital filtering, it keeps steady precision under rough seas, strong currents and fluctuating water salinity. It fully complies with IMO navigation standards and meets daily commercial vessel operation demands.

 

2. How complicated is installation and daily maintenance?
The transducer and main unit adopt integrated modular design, with clear wiring and universal mounting size for standard hull installation. No specialized tools are required. For daily upkeep, just regular cleaning of the transducer surface to remove barnacles or algae. It has no wearable mechanical parts, greatly cutting long-term maintenance costs.

 

3. Why do Doppler log readings differ from GPS speed sometimes?
It's a normal situation. Our Doppler log shows speed through water, while GPS calculates speed over ground. Tides, ocean currents and water flow will create reasonable data differences between the two. Dual-axis data can even help crews judge current direction and lateral offset for safer navigation.

 

4. Will air bubbles or propeller turbulence affect its performance?
We specially upgrade anti-interference algorithms and bubble suppression technology in R&D. The smart system filters unstable echo signals caused by propeller turbulence, hull bubbles and near-field noise. Even during high-speed sailing or frequent course changes, it can output smooth and stable speed data.

 

5. Do you offer customization and OEM/ODM service?
Absolutely. As the independent R&D and manufacturer, we can adjust transducer frequency, installation size, display mode and data logic to fit fishing boats, cargo vessels, yachts and special engineering ships. Customized functions and logo branding services are also available for bulk orders.

 

Accessories List: What does it include?

• Display Unit HDL9007
• Transceiver Unit HDL900T
• Data Unit HDL900J
• Transducer Unit A-TP820S1M2

• Display Unit Bracket
• 9-core DataCable5m
• Installation dimension diagram

• User Manual
• Certificate of conformity
• CCS certificate

• M4*20 Flat round head self-tapping screw
• M10*20 Hexagon socket flat machine screw
• M6*20 External Hexagon Flat Machine Screw

• M5*8 Black Ear Nut
• 5A Fuses

•RVRoundtubepre-insulatedcold-pressedterminal

• Black nylon cable tie 100mm
• 3.81mm&5.08mm wire clamp

 

Compared with traditional navigation speed measurement equipment, our dual axis doppler speed log breaks through technical bottlenecks in single-dimensional measurement, providing maritime operators with more comprehensive, accurate, and reliable speed data support.

 

Guide Conclusion: Looking for high-precision dual axis doppler speed log to enhance your ship's navigation performance? Our products integrate advanced sonar technology and durable design, meeting the strict requirements of marine operations. Contact us now to get customized solutions!

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