Sonardyne’s Syrinx Doppler Velocity Log (DVL)

Sonardyne into a Class of its Own

Sonardyne International Ltd., UK launched its Doppler Velocity Log (DVL) at the Ocean Business Exhibition at Southampton during April 14-16, 2015. Syrinx is Sonardyne’s first Doppler Velocity Log (DVL).

Sonardyne’s Syrinx DVL

(Source: http://www.sonardyne.com/news-a-events/all-news-articles/1265-sonardyne-launches-new-syrinx-doppler-velocity-log.html)

This is the latest addition to Sonardyne’s portfolio of acoustic devices. The company claims it is the only organization to offer inertial navigation, acoustic positioning, and DNV technologies at a single location.  

Sonardyne is a market leader in subsea inertial and acoustic navigation systems. A product of major investment by the company aimed to build the industry’s best 600kHz DVL, Syrinx is the logical evolution of Sonardyne’s existing SPRINT and 6G product lines.

Syrinx specifically addresses the needs of subsea and surface vessels needing high integrity and high performance navigation-aiding over diverse seabed types and water depths. A combination of numerous features makes it an ideal navigation instrument for Remote Operated Vehicles (ROVs) and Autonomous Underwater Vehicles (AUVs).

Doppler Velocity Logs (DVLs) & their Recent Advances

Doppler Velocity Logs (DVLs) have been used for over a decade now to collect and provide navigation data to ships, AUVs, ROVs, and human occupied vehicles (HOVs). Hitherto, DVLs could be used only on large underwater platforms such as large AUVs, work-class ROVs, and HOVs on account of their considerable sizes and weights.

Technical Data

Feature	Performance
Operating Frequency	600Hz
Long Term Accuracy	±0.1cm/s / ±0.2%
Standard Deviation: @ 1m/s @ 3m/s @ 5m/s	±0.2cm/s ±0.5cm/s ±0.6cm/s
Maximum Altitude	140m
Minimum Altitude	0.5m
Depth Rating	3,000m, 4,000m, or 6,000m
Data Output Rates (Max)	10Hz
Transit Power (Max)	218dB
Voltage Range	24V (±10%)
Communications	Concurrent RS232 & Ethernet
Internal Logging	64GB Internal Memory
Housing Material	Aluminum / Titanium

Recently however sensor manufacturers have cut down the sizes and weights of commercial off the shelf (COTS) DVLs to an extent that they can be installed and used aboard mini-ROVs.

DVLs typically use multiple transducers to measure velocity by employing water column tracking or bottom tracking. The readings are then integrated to arrive at relative displacements.

These relative displacements are then placed within the broader context of real world coordinate system through pitch, heading, and rolling sensors to calculate absolute displacement in relation to the geographical coordinate system.

DVL systems are a great way to create self contained navigation solutions to be used as input data for subsea dynamic position control mechanisms or to be used in confined access settings.

Syrinx Doppler Velocity Log (DVL): Technical & Other Details

Syrinx is available in 3,000m and 6,000m versions. For modern work-class ROVs, Sonardyne offers a 4,000m version in titanium. Users can operate, configure, and test the DVL while visualizing the data on account of an embedded web server run by the unit.

Highest In-class Precision by Combining 300kHz with 1,200kHz

(Source: http://www.sonardyne.com/products/all-products/instruments/1254-doppler-velocity-log-syrinx.html)

Configuration software is not necessary because Syrinx is connected and configured through a web browser. Chief features include:

·         Extremely Low Noise & High Precision Velocity Measurements across Diverse Depths & Numerous Challenging Seabed Types by employing the adaptive bottom lock in combination with full linear signal processing

Plus, Syrinx’s signal processing system can output data continuously at very high rates when operating at very low altitudes of less than 1m. The device is highly reliable, consistent and can navigate at high altitudes as a 300kHz DVL can and provide high resolution performance as a 1,200kHz DVL can

·         Savings in Cost & Vehicle Payload Space by virtue of its dual output capability. Syrinx can operate as part of an integrated navigation system, as a standalone DVL, or as a combination of both

Pilots and survey teams can both share output from the Syrinx when it operates in the dual mode through concurrent Ethernet and serial output capability at ping rates of up to 10Hz. Only one DVL/altitude sensor is needed for the survey crews and for ROV control

·         Rapid & Cost-Effective Service & Repairs by having individually replaceable transducers

DVLs are usually installed at the bottom-end of the vessel that makes transducers vulnerable to damage. Repairs normally mean replacing the entire transducer assembly even if only one transducer is damaged

Reprocessing & Visualization of Data through Software

(Source: http://www.sonardyne.com/products/all-products/instruments/1254-doppler-velocity-log-syrinx.html) 

·         Simple Installation, Setup, & Use as the Syrinx DVL can be fitted to the mounting brackets of existing instruments. Syrinx supports the industry standard PD4 and PD5 telegrams for smooth integration with navigation systems made by other manufacturers

Integrating Syrinx DVL with Sonardyne’s SPRINT Inertial Navigation system (INS) provides highest-quality DVL-aided navigation. The combination enables improved velocity prediction and outlier rejection by optimizing the two-way communication between these devices

Outlier is a point of observation far off from other observations. For DVLs, detection and rejection of such outlier observations drastically improves the accuracy of data and therefore of navigation

Finally

Sonardyne’s clients can look forward to immense commercial, technological, and support benefits with the company starting to supply diverse automated navigation technology under one roof. 

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