Navigator Installation Guide - Duke University Doppler Solutions Navigator Installation Guide ......

Navigator ADCP/DVL Installation Guide

P/N 957-6178-00 (September 2001)

RD Instruments Acoustic Doppler Solutions

Table of Contents 1 Introduction....................................................................................................................................... 1 2 Third Party Products ........................................................................................................................ 1 3 Over-the-Side Mounting................................................................................................................. 11

3.1 Floating Objects ................................................................................................................................11 3.2 Example of an Over-the-Side Mount.................................................................................................12 3.3 Over-the-Side Mounting Special Considerations ..............................................................................13

4 In-Hull and ROV Mounting ............................................................................................................. 13 4.1 Transducer Head Mounting Considerations......................................................................................14 4.2 Location ............................................................................................................................................14 4.3 Sea Chest In-Hull Mounting ..............................................................................................................15 4.4 Mounting Considerations ..................................................................................................................15

4.4.1 How to Mount....................................................................................................................................15 4.4.2 Orientation ........................................................................................................................................16 4.4.3 Fairing...............................................................................................................................................16 4.4.4 Acoustic Window...............................................................................................................................16 4.4.5 Air Bubbles........................................................................................................................................19 4.4.6 Flow Noise ........................................................................................................................................20 4.4.7 Corrosion and Cathodic Disbondment ..............................................................................................20 4.4.8 Ringing..............................................................................................................................................20 4.4.9 Acoustic Isolation ..............................................................................................................................21 4.4.10 Interference.......................................................................................................................................22 4.4.11 Maintenance .....................................................................................................................................22

4.5 Cabling Considerations.....................................................................................................................24 5 Computer Considerations.............................................................................................................. 25 6 Power Considerations.................................................................................................................... 26

6.1 Power Consumption..........................................................................................................................26 6.2 Current Limiting.................................................................................................................................27 6.3 Choosing a Power Supply.................................................................................................................27 6.4 Optional External Battery Pack .........................................................................................................27

7 Installation Procedures (Overview) .............................................................................................. 28 8 Alignment Procedures (Overview)................................................................................................ 28

8.1 Alignment Jig ....................................................................................................................................29 9 Specifications ................................................................................................................................. 30 10 Outline Installation Drawings ........................................................................................................ 34

967-6003 Sheet 1 .............................................................................................................................35 967-6003 Sheet 2 .............................................................................................................................36 967-6004 Sheet 1 .............................................................................................................................37 967-6004 Sheet 2 .............................................................................................................................38 967-6006 Sheet 1 .............................................................................................................................39 967-6006 Sheet 2 .............................................................................................................................40 967-6007...........................................................................................................................................41

List of Figures Figure 1. Over-the-Side Mount (WorkHorse Sentinel Shown) ...................................................... 11 Figure 2. Mounting an ADCP/DVL to a boat................................................................................. 12 Figure 3. Navigator Mounted on a ROV ....................................................................................... 13 Figure 4. Sea Chest Mounted Transducer.................................................................................... 15 Figure 5. Barnacle Damage to Urethane Face ............................................................................. 23 Figure 6. I/O Cable Wiring............................................................................................................ 25 Figure 7. Transducer Misalignment Reference Points .................................................................. 29

List of Tables Table 1: Third Party Products ....................................................................................................... 2 Table 2: Window Thickness ........................................................................................................ 18 Table 3: Wavelength of sound in seawater (1500 m/s sound speed) .......................................... 19 Table 4: Minimum Computer Hardware Requirements................................................................ 25 Table 5: Input Voltage vs Bottom-Track Range ........................................................................... 26 Table 6: Navigator Altitude (Uncertainty±1%).............................................................................. 31 Table 7: Navigator Bottom Velocity (for |V| < 10 m/s).................................................................. 31 Table 8: Navigator Water Velocity (Reference Layer*) ................................................................ 32 Table 9: Echo Intensity Profile .................................................................................................... 32 Table 10: Navigator Water Profiling .............................................................................................. 32 Table 11: Long Range Mode......................................................................................................... 33 Table 12: Standard Sensors ......................................................................................................... 33 Table 13: Transducer and Hardware............................................................................................. 33 Table 14: Environmental ............................................................................................................... 34 Table 15: Power............................................................................................................................ 34 Table 16: Outline Installation Drawings......................................................................................... 34

Navigator Installation Guide

P/N 957-6178-00 (September 2001) page 1

Acoustic Doppler Solutions


1 Introduction This book is a guide for installing the Navigator on a ROV or vessel. Use this section to plan your installation layout. You can also use this book to see what requirements you must consider before purchasing an ADCP/DVL. We recommend you distribute this information to your or-ganization’s decision-makers and installation engineers.

We are not experts in installing the Navigator aboard a ship. There are too many installation methods. We suggest you seek expert advice in this area because of its importance in ADCP/DVL performance. However, we can give you information about how others have installed their systems. In re-turn, we do appreciate receiving information about your installation and the results.

CAUTION. Always use caution when mounting the Navigator. Never rest the transducer head on a rough surface. Use foam padding to protect the transducer during handling.

2 Third Party Products RD Instruments does not necessarily endorse or recommend the products or services of the organizations listed in Table 1, page 2. We are merely pro-viding our customers with an information source to use or not use at their discretion. RD Instruments is not responsible for any product, service, or recommendation provided by another organization.


page 2 RD Instruments

Table 1: Third Party Products Organization/Contact Description Applied Coastal Research and Engineering, Inc. 766 Falmouth Road, Building A Mashpee, Massachusetts 02649 Contact: Jon D. Wood, Senior Ocean Engineer and Principal Email: [email protected] Phone: 508 539-3737 Fax: 508 539-3739

Applied Coastal Research and Engineering, Inc. fo-cuses on developing and implementing scientifically defensible solutions to problems in the marine envi-ronment. We combine state-of-science tools, including advanced instrumentation and sensor systems, nu-merical models (hydrodynamics, wave transformation, sediment transport, and water quality), and GIS appli-cations (computer mapping, image processing, surface modeling, and database design and implementation) to define and analyze physical processes in the coastal zone, continental shelf, and deep-water regions. Our specialty areas include: • Ocean current, wave and tide measurements • Numerical analyses of oceanographic data • Estuarine circulation/water quality studies • Shoreline and bathymetric change assessment • Regional sediment transport analyses • Shore protection analysis and design • Evaluation of coastal structures

Aqua Vision Zaagmolenlaan 4 3447 GS Woerden The Netherlands Contact: Dr. Peter Meijer Email: [email protected] Phone: +31 348 430384 Fax: +31 348 434254

Aqua Vision specializes in oceanographic studies. We provide several services related to ADCPs™ and other hydrological / oceanographic instruments such as data processing, data analysis, maintenance, and repair. We give courses on the use of these instruments, in-stall them aboard survey ships, and support complete measurements. Workhorse Monitor and Sentinel (1200-kHz) with bottom-tracking capability available for lease.

ASL Environmental Sciences Inc 1986 Mills Road Sidney, British Columbia, Canada, V8L 5Y3 Contact: Rick Birch or David Billenness Email: [email protected] or [email protected] Phone: +1 250-656-0177 Fax: +1 250-656-2162

ASL has been using ADCPs™ in oceanographic and river applications since 1990. We pioneered their use for mapping the circulation in hydroelectric dam fore-bays and tailraces. Recent projects include sturgeon habitat surveys in the Columbia River, and a 3-year ice keel program off Sakhalin Island using Workhorse Sentinel ADCPs™. ASL operates two 600-kHz Broad-Band, and two 300-kHz Sentinel ADCPs™, which are also available for lease.

Benco S.C. 2422 Hidden Shore Dr. Katy, TX, 77450 USA Contact: Bradley R. Benedict or Joel M. Gillet Email: [email protected] Phone: (281) 398-8585 Fax: (281) 398-8484

Benco's APS M02 is a high level Inertial Navigation System that provides attitude and position information with GPS input and during GPS or differential link out-ages. 1999 and 2000 are said to be the peaks of Solar activity and potentially of GPS outages. The APS M02 shows surprising results, in view of its consumption and price, and maintains a 5 meter preci-sion in the position for 8 to 9 minutes during GPS out-age.

C & C Technologies Contact: Jeff Fortenberry Phone: 337.261.0660 Fax: 337.261.0192

C & C Technologies is a marine survey company that specializes in cable route, pipeline, hydrographic and AUV surveys. The new HUGIN 3000 AUV is rated to 3000 meters and equipped with an Simrad EM2000, RDI Workhorse Navigator Doppler Velocity Log unit, chirp side scan sonar and subbottom profiler, inertial navigation and a fiber optic gyro.

http://www.appliedcoastal.com/

http://www.appliedcoastal.com/

mailto:[email protected]

http://www.aquavision.nl/


http://www.islandnet.com/~asl/homepage.htm




http://www.cctechnol.com/



Table 1: Third Party Products (continued) Organization/Contact Description Coastal Oceanographics, Inc. 11-G Old Indian Trail, Middlefield, CT 06455 USA Contact: Lourdes Ramos Email: [email protected] Phone: 860-349-3800 Fax: 860-349-1982

Our company, Coastal Oceanographics, Inc., has been a leader in PC-Based marine software systems for over 15 years. We have developed the very popular HYPACK hydrographic software, in use throughout the world for collecting and processing hydrographic data. Many of our users also use RDI's Acoustic Current Profiler and we are working on being able to input RDI data directly into our hydrographic software.

Compass Hydrographic Services 91 Olive Avenue Leigh on Sea Essex, UK Contact: Dr. Jon Taylor Email: [email protected] Phone: +44 (0)1702 558697 Fax: +44 (0)1702 558697

Compass Hydrographic Services is an independent, privately owned company formed in 1992 to provide oceanographic and environmental Consultancy to the Water and Dredging Industries. Based on the UK's East Coast we have worked with RDI ADCPs™ in inshore waters for several years and have developed several in-house data processing packages for analyz-ing RDI ADCP™ time-series, including the small Work-horse units. Specific capabilities include: • Measurement of oceanographic, meteorological,

and engineering parameters. • Analysis of Oceanographic Data. • Design, fabrication, and installation of oceano-

graphic data collection systems including bot-tom-mounted instrument frames with pop-up ca-pability.

• Monitoring of water quality. • Tracking of suspended sediments and discharge

plumes using Acoustic Backscatter Techniques. • Planning and monitoring of dredge material dis-

posal. • Determination of the transport and effect of

sediments, sewage, and contaminants. • Numerical modeling of waves, currents, and

tides. DRL Software Ltd. Bargate House Catteshall Lane Godalming, Surrey GU7 1LG United Kingdom Contact: John Land Email: [email protected] Phone: +44-(0)1483-860731 Fax: +44-(0)1483-426083

DRL Software has developed the Sediview Method, which is used to derive accurate suspended solids concentrations from the backscatter data obtained by RDI ADCPs™. Sediview is provided as a full survey service, or as a support and consultancy service to clients with their own equipment. Sediview is also available as a com-prehensive technology transfer package that includes training, manuals, technical support, and a multi-tasking software suite that can also be used for analy-sis and presentation of water-current data. Recent clients include Hong Kong Government, UK Environment Agency, Port of Hamburg Authority, and Associated British Ports.

http://www.coastalo.com/



http://www.drl.com/




Table 1: Third Party Products (continued) Organization/Contact Description Eden, Vorrath & Partner Schauenburgerstraße 116 24118 Kiel Germany Contact: Dirk Vorrath Email: [email protected] Phone: +49 431 5 60 66 66 Fax: +49 431 5 60 66 60

The company EDEN, VORRATH & PARTNER devel-oped a completely new ADCP data evaluation software LOG_aFlow® which is about to launch this January and was presented in 2000 on several workshops. LOG_aFlow® is a four-dimensional evaluation software that gives you • a hydrodynamic interpolation in space and time • exact hydrodynamic fields in gauge-free space • hydrodynamic maps for each time of measure-

ment in the surveyed area • complex data evaluation with distinctive results LOG_aFlow® is an easy-to-handle hydrodynamic soft-ware for hydrologic engineering. Results of LOG_aFlow® are maps displaying • flow velocity • rotation • divergence LOG_aFlow® comes with a software tool that converts RDI-rawdata into LOG_aFlow® binary data. Besides conversion the raw data are checked for consistency and plausibility.

Endeco/YSI 13 Atlantis Drive Marion, MA 02738 USA Contact: Roger Race Email: [email protected] Phone: +1 508-748-0366 Fax: +1 508-748-2543

Endeco/YSI manufactures Towed Underwater Vehicles (V-FINS). The RDI Workhorse ADCP™ can be placed in this V-FIN and towed behind a ship. Our company has experience putting ADCPs™ in Offshore Buoy Platforms to relay data by telemetry.

Evans Hamilton Seattle, WA; Houston, TX; and Washington, DC Contact: Bob Hamilton Email: [email protected] Phone: +1 281-495-0883 Fax: +1 281-495-6159

Evans-Hamilton, Inc. performs projects for a variety of government, industry, and academic clients. Specific capabilities include: • Engineering Design Support • Numerical modeling of waves, currents, tides,

and winds • Hindcasting and extreme condition determination • Measurement of oceanographic, meteorological,

and engineering parameters • Design, fabrication, and installation of data col-

lection systems • Determination of marine impacts and indicators

of climatic change • Monitoring of water quality • Tracking of suspended sediments and discharge

plumes • Planning and monitoring of dredge material dis-

posal • Determination of the transport and effect of sew-

age and contaminants

http://www.log-aflow.com/


http://www.ysi.com/


http://www.neosoft.com/~evansham/




Table 1: Third Party Products (continued) Organization/Contact Description Flotation Technologies PO Box 1171 Biddeford, ME 04005 Contact: Tim Cook, Brian Dallas Email: ADCP™@flotec.com Phone: +1 207-282-7749 -OR- Phone: +1 800-639-7806 Fax: +1 207-284-8098

Flotation Technologies provides 12 sizes of syntactic foam mooring buoys for both full-size and Workhorse ADCP™'s. Click here for Buoy Information. We also provide a full line of Trawl Resistant Bottom Mounts (TRBMs) for use with any RDI ADCP™ from the "small" Workhorse to the "large" 75-kHz. Click here for TRBM Information.

GEOS Ltd.http://www.geos.co.uk/ Gemini House Hargreaves Road Swindon, UK SN2 5AZ United Kingdom: Contact: Garry Mardell Email: [email protected] Phone: +44 (1793) 725766 Fax: +44 (1793) 706604 --------------- United States Houston, TX, Contact: Jan van Smirren Email: [email protected] Phone: +1 (713) 773-5699 Fax: +1 (713) 773-5909 --------------- Singapore Contact: Andy Brown Email: [email protected] Phone: +65 5434404 Fax: +65 5434454

Fugro Global Environmental and Ocean Sciences Lim-ited (Fugro GEOS) is a specialist consultancy with over 25 years experience in the provision of data collection, analysis and interpretation services for ocean engi-neering and marine environmental assessment appli-cations. Fugro GEOS has pioneered the use of RDI ADCPs™ to provide real-time support to drilling engi-neers (including installation of 38kHz Ocean Surveyor ADCPs™ and BOP mounted ADCPs™), and we are working on further developments in this area. The wide range of services provided by Fugro GEOS includes: • Offshore and coastal metocean measurement,

data analysis and data interpretation studies to assist with operational planning, and the as-sessment of design and operating criteria.

• Real-time current measurement systems to as-sist seismic and offshore drilling operations.

Both these areas of work involve the use of the wide range of RDI ADCPs™, with Fugro GEOS operating more than 60 instruments world-wide.

Ingenieursbureau S.D.Kamminga The Netherlands Contact: Sicco Kamminga Email: [email protected] Phone: +31 79 33160122 Fax: +31 79 33160359

ISDK provides information and assistance in solving oceanographic/hydrographic data measurement prob-lems. We provide assistance in data processing, data presentation, and data interpretation, specializing in flow and sediment transport. ADCP™: We have ADCPs™ available for hire. HORIZONTAL CURRENT PROFILING: We have ex-perience in several projects and tools for horizontal current profiling, including software for instrument con-trol and presentation. SOFTWARE: We develop software on customer speci-fication. SUSPENDED SEDIMENT: We have experience with measuring suspended sediment with ADCPs™.

http://www.flotec.com/

mailto:ADCP�@flotec.com

http://www.flotec.com/flo4.html

http://www.flotec.com/flo12.html

http://www.geos.co.uk/




http://www.isdk.nl/




Table 1: Third Party Products (continued) Organization/Contact Description HydroScience Water Resources 2404 S. Lenna Ave. Seffner, Florida 33584 Contact: Stephen R. Tarte Email: [email protected] Phone: 813-681-8918 Fax: 813-654-4666

HydroScience, Ltd. is a small water resources engi-neering company that specializes in the collection, analysis, and interpretation of hydrologic data. Our clients cover a broad spectrum that includes Universi-ties, Federal and State governments, and private in-dustry. The following is a sampling of the types of services we provide utilizing our BB-ADCP™: • Calibration of hydraulic structures • Leakage through hydraulic structures • Calibration of irrigation pumps • Sediment transport • Bathymetric surveys with DGPS • Calibration of acoustic velocity meters • Large river discharge measurements • Data collection for hydrodynamic modeling • Data collection for water-quality modeling • Data collection for hydraulic modeling • Data collection for sediment modeling For more detailed information regarding how Hydro-Science can help you organization please visit our website.

Mooring Systems, Inc. 1227 Route 28 A PO Box 413 Cataumet, MA 02534 USA Contact: Peter Clay Email: [email protected] Phone: +1 508-564-4770 Fax: +1 508-564-4773

Mooring Systems is a leader in mooring technology and provides the oceanographic community with top quality designs as well as fabricating complete mooring assemblies from buoy to anchor. Our wire rope and synthetic line assemblies are the basic component of any mooring. Besides surface buoys of all shapes and sizes we also offer Trawl Resistant Bottom Mounts and Gimbaled Bottom Tripods designed to house compact acoustic profilers along with a wide assortment of addi-tional instrumentation. Other products include Pop up Buoys, instrument frame assemblies, in-line instrument frames, pressure housings, and a wide range of compatible hardware. As custom manufacturers, modifications and novel designs are always available.

Ocean Surveys, Inc. Contact: Mark L. Kosakowski Phone: +1 (860) 388-4631 Fax: +1 (860) 388-5879

Ocean Surveys, Inc. (OSI) was founded in 1965 to provide industry and government with the technical expertise to acquire and interpret scientific data from both marine and freshwater environments. Company capabilities include hydrographic, oceanographic, geo-physical and geotechnical survey services. Ocean Surveys' diversified inventory of oceanographic and environmental instrumentation includes RD In-strument's Workhorse Sentinel and Monitor ADCPs™. In addition to providing these instruments as part of a complete survey service, they are also available on a lease basis.

http://hydroscience.com/


http://www.mooringsystems.com/


http://www.oceansurveys.com/



Table 1: Third Party Products (continued) Organization/Contact Description Oceanscan Ltd. Denmore Road Bridge of Don Abdereen AB23 8JW Contact: Carl Roemmele or Dennis Bell Email: [email protected] Phone: +44 1224 707000 Fax: +44 1224 707001

Oceanscan Ltd. provides: • Equipment hire to the ROV and hydrographic

industries (including DVL/ADCPs™). • Field personnel, surveyors, and engineering. • Application development.

The OceanScience Group 301 Sunset Drive Encinitas, CA 92024 Contact: Ron George Email: [email protected] Phone: +1 760-634-5200 Fax: +1 760-634-5275

OceanScience provides Riverboat 45 ADCP™ trima-ran for river or estuarine deployment of Rio Grande or Monitor ADCPs™. The Riverboat may be deployed using a tether from a bridge for discharge measure-ments or towed behind a boat. • Surface buoys • Subsurface buoys • Syntactic foam • ADCP™ buoys • Trawl-resistant seafloor platforms We also provide buoy lights and pressure-sensor-based wave gauges.

Open Seas Instrumentation Inc. 124 W. Petpeswick Road Musquodoboit Har-bour, NS Canada B0J 2L0 Contact: Dan Wellwood Email: [email protected] Phone: +1 902-889-3339 Fax: +1 902-889-3313

Open Seas provides oceanographic equipment to the international scientific community. Our primary focus is in two fields: • Mooring systems for oceanographic instrumenta-

tion • SUBS A2 series - ADCP™ low vibration

mooring • Subs B3 series • Low vibration mooring lines • Trawl resistant shields

• Net systems for biologists and biological oceanographers • Bioness - multi-net zooplankton systems • Mininess - smaller version of Bioness • Tucker Trawls - Single net open & close

trawl • RMT - rectangular mid-water trawl

Racal Environmental and Metocean Services RACAL SURVEY (SOUTH AFRICA) A Division of Racal Electronics South Africa (Pty) Ltd 1 Enslin Road PO Box 225 Ottery 7808 Cape Town South Africa Contact: Sidney Bilski Phone: +27-(0)21-7041600 (Switchboard) Phone: +27-(0)21-7047151 (Direct) Fax: +27-(0)21-7042520

Racal Survey (SA) has established an Environmental and Metocean Services Division in South Africa for world-wide operations. Racal Environmental and Meto-cean Services (REMOS), equipped with the most tech-nologically advanced equipment, offers a comprehen-sive range of both deep (including ultra deep) and shallow water monitoring services to companies oper-ating offshore. REMOS is the Centre of Excellence for the provision of environmental and Metocean services to all of Racal Survey's twenty-four operating companies and their clients. This ensures that Metocean campaigns under-taken by Racal Survey will be carried out profession-ally, and services of the highest possible technical quality provided.


http://www.oceanscience.com/


http://www.openseas.com/


http://www.racal.co.za/metocean/index.htm



Table 1: Third Party Products (continued) Organization/Contact Description Sea-Bird Electronics, Inc. 1808 136th Pl. NE Bellevue, WA 98005 USA Contact: Doug Bennett Email: [email protected] Phone: +1 425-643-9866 Fax: +1 425-643-9954

Sea-Bird designs and manufactures marine instru-ments that measure conductivity, temperature, pres-sure, dissolved oxygen, and related oceanographic variables. Our SBE-37-SI MicroCAT is a high accuracy, conduc-tivity, and temperature (pressure optional) sensor with-out batteries or memory (powered and commanded to sample by the host). It is easily integrated with current meters, moored instruments, remotely operated vehi-cles, AUVs, and Mini-subs. The MicroCAT can be de-ployed to 7000 meters and is constructed of titanium and other non-corroding materials to minimize mainte-nance and ensure long life. Our SBE-37-SM MicroCAT is a self-contained, autonomous recorder (fully independent, without a need for a host) that offers a "serial line sync" sampling mode. This sampling mode was developed after con-sultation with RDI to provide an easy way to synchro-nize MicroCAT sampling with RDI ADCP™ sampling. The serial line sync mode works on both RS-232 and RS-485.

Sea Sense Ltd Unit 2F Ballybrit Ind. Est. Upper Ballybrit, Galway, Ireland Contact: Dr Marcel Cure Email: [email protected] Phone: +353-91-771322 Fax: +353-91-771322

We design and manufacture a range of self-recording instruments, particularly CTD and TS. We have a new temperature and salinity instrument known as the Amara TS. We are currently working on some other products - an optical method of measuring DO, a towed digital camera system for profiling cross sections of sediment, and several acoustic systems. We have also designed and manufactured a new type of towed instrument platform - the U-KITE – which is towed from the vessel's bow and ahead of the wake and wave system of the towing vessel. U-KITE can be configured for a number of different applications, but is especially useful for positioning instruments very close to the sea surface.

Seatex Seattle, WA USA Trondheim, Norway Aberdeen, Scotland, UK Contact: David Friesen Email: [email protected] Phone: +1 206 903 8393 Fax: +1 206-903 8394

Seatex is a marine electronics manufacturer with prod-ucts for accurate positioning, heading determination, and motion sensing. The Seatex Seapath 200 provides shipboard RDI ADCP™ users with a significant advantage over the current attitude systems using GPS alone. RDI ADCP™ users operating with the Seapath 200 enjoy real-time processing of ADCP™ data and 100% avail-ability of position (<2.5m accuracy, DGPS corrected), velocity (0.03 m/s accuracy), and heading (0.05 de-grees accuracy). For details about the Seapath 200 and our other posi-tion, heading, and motion sensing instruments, visit our web site.

SMHI International Consulting Services S-601 76 Norrköping, Sweden Contact: Bo Holst Email: [email protected] Phone: +46 11 158 000 Fax: +46 11 170 207

SMHI performs, among other services, stream-flow and discharge measurements in natural and developed rivers using RDI ADCPs™. Examples of recent pro-jects include: measurements during the 1995 flooding in Norway, spillway capacity and turbine efficiency measurements for hydropower companies, and envi-ronmental monitoring for the Öresund Link Bridge con-struction (Denmark-Sweden).

http://www.seabird.com/



http://www.seatex.no/


http://www.smhi.se/en/index.htm

mailto: [email protected]



Table 1: Third Party Products (continued) Organization/Contact Description Sutron Corporation 21300 Ridgetop Circle Sterling, VA USA 20166 Contact: Patricia Hagerty Email: [email protected] Phone: +1 703-406-2800 Fax: +1 703-406-2801

ISO 9001 Certified, Sutron's real-time data collection instruments and systems with data management soft-ware, wireless and web-enabled multiple telemetry options lead the world in remote monitoring and control applications including water management, weather tracking, rainfall, stream flow, flood, and water quality monitoring as well as irrigation canal and dam control.

TSS UK Ltd 10801 Hammerly Boulevard Suite 206 Houston, TX 77043 Contact: Grant Jennings or Scott Fusselman Email: [email protected] Phone: 713-461-3030 Fax: 713-461-3099

From position and orientation systems and motion sensors installed on some of the world's most ad-vanced vessels, to pipe and cable survey systems, TSS technology is in place on and in the oceans across the world. With products widely recognized as industry standard in their sector, TSS has an uncompromising commit-ment to leading the way in the development and deliv-ery of leading edge motion sensing solutions to the ever-changing marine market. All of the TSS Motion Sensors and Aided Inertial Navi-gation Systems output the standard protocol recog-nized by RDI's ADCPs™ for ease of interfacing.

USGS - Marine & Coastal Geology Program Woods Hole, MA 02543 USA Contact: Marinna Martini Email: [email protected] Phone: +1 508-5 48-8700

Would you like to convert RDI ADCP™ data to NetCDF format? Well, you can thanks to a set of ADCP™ Tools for use with MATLAB 5.0. These tools were developed by Marinna Martini of the US Geological Survey Woods Hole Field Center in Woods Hole, MA. For detailed information on how to do this conversion using MATLAB, click here to go to Marinna's applicable web page. ADCP™ Tools is a set of MATLAB m-files that convert RDI data to NetCDF format, load the data into MATLAB, process and display the data. Beam to earth rotations can be computed if data was recorded in beam. Velocity, intensity, % good and correlation data as well as ancillary data such as temperature and sound speed are available on a beam by bin basis, and as a 3D plot. What I [Marinna Martini] offer here is a method of transferring the data to and viewing it in MATLAB.

USGS - The Lost (and Found) Instrument Net-work

The U.S. Geological Survey (in particular, Bill Strahle and Marinna Martini) maintains a web site and a mod-erated mailing list for reporting LOST and FOUND oceanographic instruments and buoys. For more in-formation, go to their web page at http://marine.usgs.gov/~mmartini/lostlist/.

U.S. Geological Survey - 3D Viewer Contact: John Donovan Email: [email protected] Phone: (916) 278-3120

A 3D viewer for ADCP™ data.

http://www.sutron.com/


http://www.tss-realworld.com/

mailto: [email protected]

http://marine.usgs.gov/~mmartini/ADCP/ADCPtools/


http://marine.usgs.gov/~mmartini/lostlist/

http://marine.usgs.gov/~mmartini/lostlist/

http://marine.usgs.gov/~mmartini/lostlist

http://wwwdcascr.wr.usgs.gov/projects/vpv/




Table 1: Third Party Products (continued) Organization/Contact Description Webb Research Corporation http://www.webbresearch.com/82 Technology Park Drive East Falmouth, MA 02536 Contact: Geoff Morrison Email: [email protected] Phone: 508 548 2077 Fax: 508 540 1686

Webb Research Corporation is an established pro-ducer of buoyancy controlled platforms, more than 1,000 vehicles are today charting the currents and in some cases T-S profiles, in the world's major ocean basins. Webb Research is proposing a shallow water tethered vehicle that may be attached to bottom mounted ADCP™ "moorings" the vehicle will periodically ascend to the surface profiling physical and or Biological vari-ables versus pressure (using third party instrumenta-tion). At the surface this vehicle will relay these data in addition to an optional subset of ADCP™ data by a telemetry method best suited to the location and mes-sage length. The device is intended to profile from a maximum depth of 30 meters, and it is anticipated that that the device will profile daily for 6 months on a single charge of propellant. Please contact Geoff Morrison with suggestions and or comments.

Woods Hole Group 81 Technology Park Drive E. Falmouth, MA 02536 Contact: G. Bowers Email: [email protected] Phone: +1 508-540-8080 Fax: +1 508-540-1001

The Woods Hole Group is a collection of affiliated oceanographic companies that currently includes Woods Hole Instrument Systems, Oceanography and Measurement Systems, Coastal Science Engineering and Planning, Aquatic Environmental Assessment, West Coast Operations, and Woods Hole Analytical Laboratories. The Group is focused on providing solutions to marine environmental problems including oceanographic and environmental monitoring systems. We have a long history of integrating ADCPs™ into these monitoring packages.

http://www.webbresearch.com/

http://www.webbresearch.com/


http://www.whgrp.com/




3 Over-the-Side Mounting The over-the-side mount is common if you want the ability to move the Navigator from one ship to another. You must make the mount as rigid as possible to limit the amount of pitch and roll applied to the ADCP/DVL. Although the tilt sensor can measure a ±20° influence, anything beyond 15° will cause bias to the data that cannot be removed. No matter what mount-ing type used, the ADCP/DVL must be below the bubble layer. Bubbles will cling to the urethane faces of the ADCP/DVL and reduce the range to almost nothing. Usually a mount somewhere aft of amidship is used. A stern mount will cause all sorts of problems due to propeller wake, bubbles, and turbulent water conditions.

NOTE. Avoid using ferro-magnetic materials in the mounting fixtures or near the ADCP/DVL. They affect the compass. Use 304 stainless steel for fresh water and 316 stainless steel for salt-water applications.

Figure 1. Over-the-Side Mount (WorkHorse Sentinel Shown) Photo courtesy of John Skadberg, US Navy SPAWAR System Center in San Diego, CA. Sent to RDI by Steve Monismith.

3.1 Floating Objects Our transducer assembly is sturdy, but we did not design it to withstand col-lisions with all floating objects. We strongly suggest you use the in-hull mount (see “In-Hull and ROV Mounting,” page 13) if this is a possibility.



3.2 Example of an Over-the-Side Mount When mounting the ADCP/DVL to a boat, use the following sequence.

• Test the ADCP/DVL

• Align the compass

• Mount to the vessel (Figure 2 shows an ADCP/DVL mounted to a boat).

1. Hand winch with cable or rope.

2. Boat cleat to tie off the lower end of the channel.

3. Aluminum channel, 5" base x 2" high x 3/16" thick. You need to deter-mine how long the channel needs to be as the drawing is not to any scale. The channel should be notched for the end-cap flange of the Housing Assembly. This will give the system a positive lock after the ADCP/DVL has been strapped to the channel.

4. Pivot housing - This could be a very heavy one-piece bent housing, or a three-piece assembly. Bolt the pivot housing to the deck of the boat (or buoy).

5. Nylon strap clamps - Two clamps are needed. Place some rubber or foam between the housing and the aluminum channel before clamping to protect the ADCP/DVL.

2

1

3

4

5

5"

2"

3/16"

ALUMINUM CHANNEL DETAIL

Figure 2. Mounting an ADCP/DVL to a boat



3.3 Over-the-Side Mounting Special Considerations Use the following suggestions when mounting the ADCP/DVL to a moving platform.

• It is desirable to rigidly mount the ADCP/DVL to the vessel. You want to avoid the free spinning of the ADCP/DVL in this applica-tion. The ADCP/DVL must stay in the water at all times.

• The ADCP/DVL must be mounted deep enough so that turbulence caused by its movement through the water does not allow air bub-bles to be attached to the transducer faces.

• Avoid mounting the ADCP/DVL near motors and thrusters. They cause air bubbles and will cause bias to the internal compass.

• Avoid mountings that will cause the ADCP/DVL to see severe accelerations.

4 In-Hull and ROV Mounting The in-hull or ROV mounted ADCP/DVL is common when it is intended to keep the system on a single vessel or when over-the-side mounting is not practical for your vessel. For this type of mounting, there are issues of beam clearance and access.

Figure 3. Navigator Mounted on a ROV



4.1 Transducer Head Mounting Considerations You must consider several potential problems before installing the trans-ducer head assembly. Read this section before deciding where to install the transducer assembly. See the outline installation drawings for specifica-tions on our standard ADCP/DVL transducer heads.

4.2 Location Ideally, you want to install the transducer head:

• Where it is accessible both internally (for access to transducer elec-tronics) and externally (to remove biofouling).

• Away from shipboard protrusions that reflect ADCP/DVL energy. Allow for a reflection-free clearance of 15° around each beam (see the outline installation drawings).

• Away from other acoustic/sonar devices, especially those operating at the same frequency (or harmonic) of the ADCP/DVL.

• Close to the ship’s fore-to-aft centerline. As distance from the cen-terline increases, vertical accelerations caused by the roll of the ship also increase. These accelerations can cause additional uncertainties in ADCP/DVL velocity measurements.

• As far away as possible from thrusters and motors.

• If mounting to a ROV that tends to kick up sediment, mount the DVL as far forward as possible.

Other considerations may be:

• Ease of installation.

• Portability (wanting to move the instrument from vessel to vessel).

• Permanent installation. With all of these choices there are good and bad points. We will show you several options for installation and then go through specific concerns that you may have to deal with once you install or mount the Navigator.



4.3 Sea Chest In-Hull Mounting A sea chest (Figure 4) is a fixture that surrounds and holds the transducer head, protecting it from debris in the water. The bottom of the sea chest must be open to seawater to allow the acoustic beams to pass through freely. If using a sea chest interests you, call us for the latest information. Ask for Application Note 7 - Conceptual Design of a Sea Chest for an RDI ADCP/DVL Transducer.

VENT PIPE

MINIMUM 0.25"

Figure 4. Sea Chest Mounted Transducer

4.4 Mounting Considerations Now that we have shown you the main methods of mounting the ADCP/DVL, you must be aware of issues that may cause reduction in range, biased data, fouling, and other performance related considerations.

4.4.1 How to Mount The DVL should be mounted from the end cap or by a clamp around the body. The mounting surface should be electrically isolated from the DVL (i.e. with rubber between the touching surfaces). This is to ensure that the sacrificial anode works on the DVL and not the clamps.

There are four bolt holes on the 300/600kHz end-cap/housing assembly that can be used for mounting. There are eight bolt holes used to hold the 1200kHz end cap on. For mounting, it is recommended that only four of the bolts are removed from the end cap, and use those four bolts for mount-ing. It is recommended that every other bolt be used.



4.4.2 Orientation We recommend you mount the transducer head with Beam 3 rotated to a ship-relative angle of 45° (see “Alignment Procedures (Overview),” page 28 and Figure 7, page 29). This causes the magnitude of the signal in each beam to be about the same. This improves error rejection, reduces the ef-fect of ringing (see “Acoustic Isolation,” page 21), and increases the ADCP/DVL’s effective velocity range by a factor of 1.4. If you align Beam 3 at an angle other than zero, you must nullify this offset. You can do this using the EA command (see the Workhorse Commands and Output Data Format Guide).

Use the ship’s roll and pitch reference to mount the transducer head as level as possible. If the head is not level, depth cell (bin) mapping will be incor-rect. Large misalignments can cause large velocity measurement errors. If you cannot mechanically make the transducer head level, you can use a di-rect command to enter offset values for roll and pitch.

4.4.3 Fairing A fairing is a structure that produces a smooth outline and reduces drag or water resistance. The fairing also diverts floating objects away from the transducer. A fairing that is shaped like a teardrop, sloped such that the leading edge (closer to the bow) is higher than the back edge, and extends below the hull (typically 12 inches) will divert the air bubbles away from the transducer faces.

4.4.4 Acoustic Window While we do not fully understand windows, we do believe that windows can be used to produce overall performance improvements in vessel-mounted ADCP/DVLs. Additionally, if the ship operates where there is danger of barnacle damage or a high density of ice or other floating objects, then the use of an acoustic window is the only option.

It is theoretically possible to use a window successfully, however there are several advantages and disadvantages to consider before using an acoustic window. Advantages

• Well will not fill with air bubbles caused by the ship moving through the surface water, see “Sea Chest In-Hull Mounting,” page 15

• Flow noise is reduced, see “Flow Noise,” page 20.

• The well can be filled with fresh water to limit corrosion.



• Barnacles can not grow on the transducer faces. Barnacle growth is the number one cause of failure of the transducer beams.

• The transducer is protected from debris floating in the water. Disadvantages

• The range of the ADCP/DVL will be reduced because the window can and will absorb some of the transmit and receive energy.

• The transmit signal could be reflected into the well, causing the well to “ring” like a bell. This will cause the data being collected during the ringing to be biased. Some ships have reported a loss in range as great as 50 meters. The ringing may be damped by applying sound absorbing material on the well walls (standard neoprene wet suit ma-terial has been found to work well), see “Ringing,” page 20.

• The transmit signal could be reflected off the window and back into the other beams.

Our experience has allowed us to put together some minimum specific rec-ommendations:

Window orientation. The acoustic window should be flat and parallel to the transducer mounting plate. Note this is not an absolute requirement. However, if the water temperatures inside the window and outside the win-dow are not the same, all four beams will be refracted and actual velocity components will be rotated into a new coordinate system. In particular, some of the horizontal velocity will appear as a vertical velocity.

Window material. Important acoustic properties of the window include acoustic refractive index (which should be as close as possible to that of water), insertion loss (which should be as small as possible) and speed of sound. There are two acoustic refractive indices: one for shear waves and one for plane waves. The acoustic refractive indices are simply the ratios of speed of sound in water to speed of sounds in the material. Insertion loss combines absorption and reflection of sound, and it depends on both the thickness and the material properties of the window. In particular, you should avoid using window thickness equal to odd multiples of shear mode quarter-waves (Dubbelday and Rittenmeyer, 1987; Dubbleday, 1986). Re-fer to Selfridge (1985) and Thompson (1990) for more information. Note that the speeds of sound in plastics decrease with increasing temperature and that causes the resonant frequencies to shift. This can be a large effect. Neither Selfridge nor Thompson has much information on the temperature coefficients of sound speeds.

Our experience has shown that Polycarbonate windows are very good for the WorkHorse ADCP/DVLs. The thickness of the materials depends on



the frequency you intend to use. Table 2 will help to choose the maximum thickness you should use.

NOTE. One concern with window selection is that it be able to support the weight of the water inside the well once the ship is dry-docked. RDI recommends that you always fill/drain the well at the same time that you are either filling/draining the dry dock area.

Table 2: Window Thickness Frequency Thickness

300 0.5 inches

600 0.25 inches

1200 0.25 inches Spacing between window and transducer. The primary geometrical factor in design of windows is the reflection of a beam into another beam, causing crosstalk between the beams. The distance of the transducer from the win-dow should be at least 0.25 to 0.5 inches. If installed farther than 0.25 to 0.5 inches, then be sure your window aperture is large enough to clear the OD convex beams.

The optimum distance for the bottom of the transducer assembly from the window is 0.25 inches ±0.125 inches. Never allow the transducer to touch the window. The farther away the transducer is from the window, the more the sound is reflected off of one beam and then reflected into another beam. Example One of our representatives uses a 0.25-inch thick window. He then drills two 30mm holes in the window along the edges. The inside walls are painted with anti-fouling paint. This allows the water to be full of anti-foulant during the time the ship is docked, which is when the barnacle growth occurs. The holes allow the water to exchange when the ship is in motion and allows for draining when the ship is dry-docked (a 0.25” win-dow will not support the weight of the water). He has never had a failure with the window, and has seen only a minimal loss in range (5-30 meters).

It is best if the window is parallel to the bottom edge of the transducer. If the window is at an angle to the transducer, it will change the absorption. We do not have experience with different angles, but we have had custom-ers use domes or have the window follow the contour of the ship bottom without noticeable degradation of the data.

Acoustically-absorbing sea chest liner. A sound absorbing material should be used inside the sea chest to minimize the effects of sound ringing within the sea chest. The material should be a minimum of one wavelength thick (include the sound speed of the absorbing material when calculating the size



of a wavelength). Approximate wavelengths of sound in seawater are given below in Table 3. Using standard neoprene wet suit material has been found to work well with 300 and 600hKz frequency ADCP/DVLs.

Table 3: Wavelength of sound in seawater (1500 m/s sound speed) FREQUENCY (kHz) WAVELENGTH (mm)

300 5

600 2.5

1200 1.25

Fluid in the sea chest. The sea chest should be filled with fresh water. Seawater can be used, but at the cost of increased corrosion. Seawater should not be circulated through the sea chest unless the sea chest has been painted with anti-fouling paint. The pressure within the sea chest should be adjusted to keep the window from bowing in and out, and thereafter, the volume should be kept constant.

4.4.5 Air Bubbles Design your installation to minimize the volume of air bubbles in the path of the acoustic beams. Air bubbles attenuate (weaken) the signal strength and reduce the ADCP/DVL profiling range. Ships with a deep draft or a non-flat bottom have fewer problems with bubbles. Ways to reduce bubble flow vary with ship characteristics, but two options are available. Mount the transducers below or away from the bubble layer.

• The flow layer is usually within the first two feet below the hull. Bubbles can get trapped in this layer. Mounting the transducer head amidship on the fore-to-aft centerline may help. For ships with pro-pulsion systems that make large amounts of bubbles, use a mounting technique that lets you lower the transducer head below the hull while underway.

NOTE. If you use locally made or existing extension hardware instead of the hardware available from RDI, you may need to make an adapter plate to connect your hardware to our transducer head. Please call us for the exact dimensions and layout of our transducer head bolt holes for your system.

• Divert the bubble layer so it flows around the transducers - You can use fairings to alter the bubble flow. An acoustic window (see “Acoustic Window,” page 16) may help reduce the bubble problem, but can cause ringing (see “Acoustic Isolation,” page 21) and at-tenuation problems.



4.4.6 Flow Noise Water flowing over the transducer faces increases the acoustic noise level, which decreases the profiling range of the ADCP/DVL. You can reduce the flow across the transducer faces with a sea chest, fairing, or acoustic win-dow.

4.4.7 Corrosion and Cathodic Disbondment Your ADCP/DVL is made of naval bronze, aluminum, or other materials. Standard anode protection used for the ship should be installed outside of the well of the transducer head. Mounting of ship’s standard anode protec-tion outside of the transducer well will typically protect the parts that may corrode. However, you should plan regular inspections of mounting hard-ware for signs of corrosion. Replace and parts that are questionable (corro-sion can be further reduced if the well is covered with a window and then filled with fresh water).

4.4.8 Ringing The ADCP/DVL transmits an acoustic pulse into the water. The main lobe of this pulse bounces off particles in the water and the signals returned from these particles are used to calculate the velocity of the water.

As stated, the main lobe of the transmitted pulse is what we are using to process and calculate a velocity. The transmitted pulse, however, is made up of many side lobes off the main lobe. These side lobes will come in con-tact with metal of the transducer beam itself and other items in either the water or the well.

The energy from the side lobes will excite the metal of the transducer and anything bolted to the transducer. This causes the transducer and anything attached to it to resonate at the system’s transmit frequency. We refer to this as “ringing.”

If the ADCP/DVL is in its receive mode while the transducer is ringing then it will receive both the return signals from the water and the “ringing.” Both of these signals are then processed by the ADCP/DVL. The ringing causes bias to the velocity data.

All ADCP/DVLs “ring” for some amount of time. Therefore, each ADCP/DVL requires a blanking period (time of no data processing) to keep from processing the ringing energy. Each ADCP/DVL frequency has a dif-ferent typical ringing duration. The typical ringing period for each ADCP/DVL frequency is as follows; 300kHz ADCP/DVLs is 2 meters, 600kHz ADCP/DVLs is 1.5 meters, and 1200kHz ADCP/DVLs is 0.8 me-ters. These typical ringing values are recommended as the minimum setting for all ADCP/DVLs using default setups.



It should be noted, on some installations the effects of ringing will last longer than the recommended settings above. For example, the effects of ringing will last longer if the transmit signal becomes trapped inside the transducer well. This can occur because the well itself is ringing with the transducer or when windows covering the opening of the well reflect the signal back inside the well.

The window causes the transmit signal to reflect back into the well due to the difference in impedance between the window and the water. When the transmit signal is reflected in the well it becomes trapped and this results in longer ringing periods. To keep from processing this signal, the blanking period must be increased.

Line the inside walls of the well with a sound absorbing material to damp the ringing effect. Using standard neoprene wet suit material has been found to work well.

4.4.9 Acoustic Isolation Try to minimize the acoustic coupling between the transducer head and the ship. Without adequate acoustic isolation, the transducer output will “ring” throughout the ship and feeds back into the ADCP/DVL receive circuits. Ringing causes bias errors in water-track velocities and results in the loss of data in the closest depth cells (bins). Reflections inside a sea chest with an acoustic window also can cause ringing.

You can attain acoustic isolation several ways. At a minimum, use gaskets to isolate all contact points between the ship and the transducer head. De-sign your installation for:

• A minimum number of contact points between the transducer head and the ship.

• Minimal contact area.

• Single points of contact for positioning and support (when possible). You also should try to separate the transducer head from the ship using in-termediate connections. This is because direct connections transfer the most acoustic energy. Texas A & M used the following installation tech-nique and had minimal ringing problems.

• Transducer mounted to a thin steel plate

• Steel plate positioned with three pins set into mounting holes on the hull; pins isolated with gaskets

• Steel plate held in place with four I-beams welded to a frame

• Frame bolted to another frame and separated by gaskets



• Second frame bolted to the ship and separated by gaskets Acoustic isolation from other acoustic devices on the ship is also necessary. You can do this using the following techniques.

• Mount the other acoustic devices as far apart as possible.

• Make sure neither the main lobes nor the side lobes of the acoustic devices point at the transducers, including acoustic reflections.

• Try not to operate devices that use the same frequency or a harmonic of the ADCP/DVL’s frequency.

4.4.10 Interference Interference from other acoustic devices can cause velocity and direction biases. In extreme cases it the can prevent the DVL from operating. How-ever, it is possible to avoid this circumstance. If the other device operating frequency is within 25% of the operating frequency of the DVL or is an odd multiple of the DVL frequency (e.g. DVL is 307,200Hz, then a third har-monic (multiple) of another device would be 100,000Hz) then you may want to make both devices transmit at the same time. By transmitting at the same time the two systems usually do not interfere.

The DVL transmits a pulse or series of pulses that contain four carrier cycles. The transmit bandwidth is 25% (Sin χ / χ) and the front end receive bandwidth is determined by the transducer and is 40% about the carrier frequency.

4.4.11 Maintenance The Maintenance guide explains routine maintenance procedures. You rarely need access to the electronics inside the transducer head. However, one external maintenance item is important enough to mention here as it may affect how you install the transducer head.

Objects deployed within about 100 meters (328 feet) of the surface are sub-ject to the buildup of organic sea life (biofouling). This means WorkHorse Navigators are subject to biofouling. Soft-bodied organisms usually cause no problems, but hard barnacle shells can cut through the urethane trans-ducer face causing transducer failure and leakage into the ADCP/DVL (see Figure 5, page 23).



Figure 5. Barnacle Damage to Urethane Face

The best-known way to control biofouling is cleaning the ADCP/DVL transducer faces often. However, in many cases this is not possible. The other alternatives include the use of a window or some sort of anti-foulant protection.

Some of our users have had success applying a thin coat (≈4 mm; ≈0.16 in.) of either a 50:50 mix of chili powder and Vaseline or chili powder and sili-cone grease to the transducer faces. The chili powder should be the hottest that can be found. Water flowing across the transducers will wash this mix away over time. The silicone mixture tends to last longer.

Some organizations may decide to use antifouling grease. However, most antifouling greases are toxic and may cause problems. Recent tests suggest antifouling grease may cause the urethane on the transducer faces to de-velop cracks. Warmer temperatures accelerate this effect.

The other method is to use antifoulant paint. At present, we recommend the following antifouling paint manufacturer and paint brand: Courtalds Fin-ishes Interlux brand paints, US Telephone: 908-686-1300, Web Page: www.interlux.com.

http://www.interlux.com/



CAUTION. 1. Read the Material Safety Date Sheet before using any of the listed

solvents and paints.

2. Some antifouling coatings may not be legal for use in all areas. Check with your local environmental agency before using the antifouling paint.

3. Do not arbitrarily use antifouling paints. Be aware that antifouling paints can accelerate the dezincification corrosion of brass. Once initiated, dezincificatioin will rapidly destroy the brass.

4. RDI no longer recommends the use of Nopcocide for the prevention of biofouling. If using antifouling grease, remove it immediately after recovering the ADCP/DVL.

5. Antifouling grease is toxic. Read the product safety data sheet before using the grease. Wear gloves and a face shield when applying the grease. If the skin comes in contact with the grease, immediately wash the affected area with warm, soapy water.

6. When possible, do not coat the transducer faces with cuprous oxide or related paints that contain chemicals such as copper, chrome, or arsenic. These paints advance the corrosion of the transducer assembly and will cause the urethane to separate from the transducer cups.

7. All US Coastal States prohibit the use of tributyl-tins on boat hulls. The European Economic Commission has released a draft directive that would prohibit the use of many organo-tins after July 1989. We strongly recommend you obey your local laws.

4.5 Cabling Considerations Use care when routing the Input/Output (I/O) cable through bulkheads, deck plates, cable runs, and watertight spaces. Make allowances in cable length and engineering design plans for cable routing. When necessary, use strain reliefs on the cable.

The Navigator is shipped with a pigtail I/O cable. The I/O cable connects the transducer head to the computer. The transducer-end connector is molded on, so you can use it below the waterline. Determine what commu-nication setting you will be using and the connector type required (not sup-plied by RDI) and wire the pigtail cable as shown in Figure 6, page 25. The cable is custom-made in lengths specified by the user. Route this cable so:

• It does not have kinks or sharp bends.

• You can easily replace it if it fails.



76

5

4

12

3

12564

37

POWER +POWER -

COMMUNICATION RETURN

RS-232 IN / RS-422 OUT ARS-232 OUT / RS-422 OUT B

RS-422 IN ARS-422 IN B

BLKWHTBLUBRNGRN

REDYEL

Figure 6. I/O Cable Wiring

NOTE. Color code is shown for reference only. Your cable may be different.

The I/O end-cap connector part number is LPMBH-7-MP from Impulse. The connector on the cable has to be an LPMIL-7-FS. It has 7 pins: two power lines, five for RS422, or three RS232 and two RS485.

5 Computer Considerations We designed the Navigator ADCP/DVL to use a Windows® compatible computer. The computer controls the ADCP/DVL and displays its data, usually through our DumbTerm or SHIPTRAK (DOS only) programs. Table 4 lists the minimum computer requirements.

Table 4: Minimum Computer Hardware Requirements Windows® 95, Windows® 98, or Windows® NT 4.0 with Service Pack 4 installed

Pentium class PC 233 MHz (350 MHz or higher recommended)

32 megabytes of RAM (64 MB RAM recommended)

6 MB Free Disk Space (20 MB recommended)

One Serial Comports (two High Speed UART Serial Comports rec-ommended)

Minimum display resolution of 800 x 600, 256 color (1280 x 760 High Color recommended)



6 Power Considerations The AC power adapter provided by RDI is designed for testing where AC power is available. It provides up to 30 watts at 24 VDC. For deployments, the Navigator requires a power supply designed to supply between 20 to 60 VDC, 25 watts. Navigator power requirements are discussed below.

Sonar performance depends on supply voltage, but not very strongly. The processing electronics use a DC/DC converter so their function is independ-ent of the supply voltage over the 20 to 60 volt range. However, the raw supply voltage is provided directly to the transmitter so that the transmitted acoustic power is proportional to Vin

2. Table 5 shows the bottom-track range (assuming a salinity of 35 ppt and temperature of 5° C) versus supply voltage:

Table 5: Input Voltage vs Bottom-Track Range Bottom-Track Range (meters) Power Supply

Voltage (VDC) 1200kHz 600kHz 300kHz

20 26 92 243

24 27 94 251

30 28 98 260

40 29 101 271

50 30 104 279

60 30 105 284

Many customers have successfully operated the Navigator using 24 volts. It may be worth the cost of providing a higher supply voltage to achieve the maximum bottom-tracking range.

6.1 Power Consumption The average power drawn by a Navigator pinging at its maximum rate at maximum altitude is 3 Watts for a 1200kHz, 5 Watts for a 600kHz and 16 Watts for a 300kHz. This is based on an input voltage of 32 volts. There is a constant background power consumption of 2.2 watts for the processing electronics as long as the Navigator does not “go to sleep.”

The average power consumption depends upon the transmit duty cycle which is a function of many factors. For a Navigator pinging at its maxi-mum rate, the maximum duty cycle is about 13%. By reducing the ping rate, the duty cycle is reduced and therefore overall power consumption may be reduced.

The Navigator contains a capacitor that provides filtering of the high power consumption during transmit. This means that the Navigator should not be



adversely affected by reasonable variations in the power supply voltage. It also means that the Navigator should not unduly affect the power supply circuit.

6.2 Current Limiting Peak current drawn by the Navigator is never more than 3 amps due to a current limiting circuit that is provided to prevent blowing a 3 amp internal fuse. At start up this translates to 96 Watts at 32V input.

Note that the power supply must be able to provide at least 10 volts con-tinuously at a current draw of 0.4 amps to get the processor started.

6.3 Choosing a Power Supply There are two keys to choosing a power supply for the Navigator:

• Including loss in the wiring, the power supply must be able to sup-ply more then 10 Volts to the Navigator’s input connector if the there is 0.4 amp being drawn by the Navigator. This is the minimum voltage needed to start the Navigator.

• Should the supply current limit it must not turn it’s output com-pletely off. The power supply should maintain current flow into the Navigator (“fold back”, not “hiccup”). If the supply turns off to pro-tect itself, it will cause the Navigator’s internal discharge circuit to discharge the internal capacitors and the Navigator will not start.

CAUTION. When using an external DC power supply, set the power supply to the proper voltage BEFORE connecting it to the Navigator, and then turn the power supply OFF when connecting it to the Navigator. Do NOT exceed the rated voltage or equipment damage may occur.

6.4 Optional External Battery Pack If both the optional External Battery Pack and power supply are connected, the Navigator will select the highest voltage source for use. The External Battery Pack (when fresh) supply +42 VDC and the AC power adapter out-put is +24 VDC. The Navigator will draw all power from the battery if the battery voltage is above +24 VDC (the power supply will have no effect).

NOTE. The +24 VDC AC adapter does not override the battery voltage! Substitute your own power supply with a voltage of +45 to 60 VDC to override the +42 VDC alkaline battery packs.



7 Installation Procedures (Overview) Read these steps before doing them. In general, follow them in the order listed. Some may differ for your installation, so modify them as necessary. Some can be done simultaneously (e.g., hardware installation and software loading). If you have problems or questions, call us.

a. On receipt of the system, read the Read This First book.

b. Before installing the system, test the transducer right out of the shipping container. Do the following.

1. All power to the system DISCONNECTED.

2. Review “Power Considerations,” page 26.

3. Connect the I/O cable from the computer to the ADCP/DVL.

4. Connect the power cable to the I/O cable connector and apply power to the system (the Navigator User’s Guide shows all cable connec-tions for testing).

5. Follow testing procedures in the Test Guide. Test the system. If er-rors occur, use the Troubleshooting book.

c. Prepare the system for shipboard installation. Disconnect all power to the system. Disconnect all interface cables.

d. Review “Transducer Head Mounting Considerations,” page 14. Install the transducer head. Mechanically align the system (see “Alignment Procedures (Overview),” page 28).

e. Review “Computer Considerations,” page 25. Install the computer.

f. Review “Cabling Considerations,” page 24. As necessary, route and connect the I/O cable.

g. As necessary, load the software on the computer’s hard drive. See the Navigator User’s Guide for help on using the software.

h. Do the Sea Acceptance testing (see the Test Guide). The Sea Accep-tance tests include a Bottom-track (range, accuracy) check.

8 Alignment Procedures (Overview) The mechanical alignment of the transducer head is important to ADCP/DVL data accuracy. Mechanically mount the head as close as possi-ble to your reference point. This is usually with the Beam 3 mark at 0° or 45° relative to the ship’s fore-to-aft centerline. You also must mount the transducer head as level as possible using the ship’s roll and pitch refer-ences. Review the “Transducer Head Mounting Considerations,” page 14 for alignment considerations.



When the Navigator is aboard a vessel, the mechanical alignment of the transducer head (Beam 3 mark) is usually aligned with the ship’s fore-to-aft centerline (0°), or rotated 45° clockwise. To conceptually determine the misalignment angle, visually hold the ADCP/DVL still and turn the ship gyro’s north reference to match the ADCP/DVL’s north reference. For ex-ample, if the Beam 3 mark is pointing at the bow (Figure 7), the misalign-ment angle is zero. If the Beam 3 mark is pointing 45° to starboard (Figure 7), you must turn the ship a +45° to align the two north reference points. Conversely, if the Beam 3 mark is pointing 45° to port, you must turn the ship a -45° to align the two reference points.

NOTE. We recommend you mount the Navigator with Beam 3 rotated to a ship-relative angle of 45°. This causes the magnitude of the signal in each beam to be about the same. This improves error rejection, reduces the effect of ringing, and increases the Navigator’s effective velocity range by a factor of 1.4.

BEAM 3 AT 0 DEGREESTO SHIP CENTERLINE

FORWARD

3

4

12

BEAM 3 ROTATED 45 DEGREESFROM SHIP CENTERLINE

FORWARD

3

2 4

1

Figure 7. Transducer Misalignment Reference Points

8.1 Alignment Jig The alignment jig is a straight bar with two screw holes to attach it to the transducer head. Use the jig to help you align the transducer. Mount the transducer in the mounting frame/hardware but allow the transducer to still be able to be rotated. Attach the jig to the transducer using the provided screws. Use the jig to rotate the transducer to the proper angle. Tighten the mounting hardware so that the transducer will not rotate.

NOTE. If your Navigator ADCP/DVL has the optional pressure sensor, the pressure sensor will interfere with the alignment jig.



9 Specifications A brief review of ADCP/DVL operation may help you understand the specifications listed in this section.

NOTE. The specifications and dimensions listed in this section are subject to change without notice.

The ADCP/DVL emits an acoustic pulse called a PING. Scatterers that float ambiently with the water currents reflect some of the energy from the ping back to the ADCP/DVL. The ADCP/DVL uses the return signal to calculate a velocity. The energy in this signal is the echo intensity. Echo intensity is sometimes used to determine information about the scatterers.

The velocity calculated from each ping has a statistical uncertainty; how-ever, each ping is an independent sample. The ADCP/DVL reduces this statistical uncertainty by averaging a collection of pings. A collection of pings averaged together is an ensemble. The ADCP/DVL’s maximum ping rate limits the time required to reduce the statistical uncertainty to accept-able levels.

The ADCP/DVL does not measure velocity at a single point; it measures velocities throughout the water column. The ADCP/DVL measures veloci-ties from its transducer head to a specified range and divides this range into uniform segments called depth cells (or bins). The collection of depth cells yields a profile. The ADCP/DVL produces two profiles, one for velocity, and one for echo intensity.

The ADCP/DVL calculates velocity data relative to the ADCP/DVL. The velocity data has both speed and direction information. If the ADCP/DVL is moving, and is within range of the bottom, it can obtain a velocity from returns off the bottom. This is called bottom tracking. The bottom track information can be used to calculate the absolute velocity of the water. The ADCP/DVL can get absolute direction information from a heading sensor.

The following tables list the specifications for the WorkHorse ADCP/DVL. About the specifications:

a. All these specifications assume minimal ADCP/DVL motion - pitch, roll, heave, rotation, and translation.

b. Except where noted, this specification table applies to typical setups and conditions. Typical setups use the default input values for each parameter (exceptions include Pings Per Ensemble and Number of Depth Cells). Typical conditions assume uniform seawater velocities at a given depth, moderate shear, moderate ADCP/DVL motion, and typical echo intensity levels.



c. The total measurement error of the ADCP/DVL is the sum of:

• Long-term instrument error (as limited by instrument accuracy).

• The remaining statistical uncertainty after averaging.

• Errors introduced by measurement of ADCP/DVL head-ing and motion.

d. Because individual pings are independent, the statistical uncertainty of the measurement can be reduced according to the equation:

Table 6: Navigator Altitude (Uncertainty±1%) System

Frequency 1200kHz 600kHz 300kHz

Maximum Altitude (m) 30 90 200

Minimum Altitude (m) 0.5 0.7 1.0

Table 7: Navigator Bottom Velocity (for |V| < 10 m/s) Precision (cm/s)* 1200 kHz 600 kHz 300 kHz

V=1.0 m/s 0.3 0.3 0.3

V=3.0 m/s 0.4 0.5 0.6

V=5.0 m/s 0.5 0.6 0.8

Accuracy (cm/s) ±0.2% ±0.2 ±0.3% ±0.2 ±0.4% ± 0.4

Maximum Ping Rate** 1 to 10 Hz 0.5 to 7 Hz 0.5 to 7 Hz

* Water and Bottom velocity precision are standard deviations of horizontal velocities for single pings. The standard deviation for an ensemble of pings will decrease proportional to the square root of the number of pings averaged together.

* Single Ping Precision calculated for an altitude of one-half maximum altitude for a given frequency.

** Ping rates vary due to altitude, baud rate, and amount of water profiled.



Table 8: Navigator Water Velocity (Reference Layer*) Range limits(m) 1200 kHz 300 kHz

Minimum 0.25 1.0

Maximum 18 110

Short-term error: Precision (cm/s)**

Ref. Layer Size=1.0 m 6 15




Long-term Error: Accuracy (cm/s) ±0.2% ±0.01 ±0.4% ±0.4

Ping Rate*** 1 to 10 Hz 0.5 to 7 Hz

* Reference layer maximum ranges are for typical water conditions: 35% salinity, 10°C temperature.

** Water and Bottom velocity precision are standard deviations of horizontal velocities for single pings. The standard deviation for an ensemble of pings will decrease proportional to the square root of the number of pings averaged together.

** Single Ping Precision calculated for an altitude of one-half maximum altitude for a given frequency.

*** Ping rates vary due to altitude, baud rate, and amount of water profiled.

Table 9: Echo Intensity Profile Vertical resolution Depth cell size

Dynamic range 80 dB

Precision ± 1.5dB (relative measure)

Table 10: Navigator Water Profiling Depth Cell

Size1 Nominal range 15m2

1200kHz Nominal range 55m2

600kHz Nominal range 135m2

300kHz

Vertical Resolution

Range3 (m)

Std. dev.4 (mm/s)

Range3 (m)

Std. dev.4 (mm/s)

Range3 (m)

Std. dev.4 (mm/s)

0.25m 12 182 0.50m 13 66 40 182 1.0m 15 30 45 66 97 182 2.0m 16 18 50 30 110 66 4.0m 56 18 123 30 8.0m 138 18

NOTES

1. User’s choice of depth cell size is not limited to the typical values specified.

2. Longer ranges are available.

3. Range, which depends on cell size, is specified here for BroadBand mode at 5° C, typical ocean back-scatter, and nominal 48 VDC power.

4. Broad bandwidth mode single-ping standard deviation

NOTE. Water Profiling is an upgrade feature for the Navigator.



Table 11: Long Range Mode Range (m) @ 33VDC Range (m) @ 48VDC Depth Cell Size (m) Std. dev. (mm/s) 1200kHz 19 20 2 35 600kHz 67 70 4 38 300kHz 165 175 8 38

Range, which depends on cell size, is specified here for narrow bandwidth mode at 5° C, typical ocean backscatter, and nominal 33 VDC battery power (Sentinel) and 48VDC input power (Mariner/Monitor).

Table 12: Standard Sensors Temperature (mounted on transducer)

Range: -5° to 45° C

Precision: ± 0.4° C

Resolution: 0.01°

Tilt

Range: ± 15°

Accuracy: ± 0.5°

Precision: ± 0.5°

Resolution: 0.01°

Compass (fluxgate type, includes built-in field calibration feature)

Accuracy: ± 2°1

Precision: ± 0.501

Resolution: 0.01°

Maximum tilt: ± 15°

Note: 1) @ 60° magnetic dip angle, 0.5G total field

Table 13: Transducer and Hardware 1200kHz 300kHz 600kHz

Available Frequency 1,228,800 actual 307,200 actual 614,400 ac-tual

Beamwidth 1.2° 3.9° 2.0°

Beam Angle 30°

Configuration 4-beam, convex

Housing & Transducer material 6061 or 7075 Aluminum or Titanium

External connector 7-pin low-profile

Internal memory Memory card not included with Navigator models. Two PCMCIA card slots are available (16 to 220 Mb each).

Communications Serial port selectable by switch for RS-232 or RS-422. ASCII or binary output at 1200 to 115,400 baud.



Table 14: Environmental Standard depth rating 2000m (Optional 3000 and 6000-meter housings available)

Operating temperature -5° to 45°C

Storage temperature -30° to 75°C

Battery Storage Batteries should be stored in dry air with a temperature O° C to 21° C

Battery Shelf Life Use within one year.

Weight in air/water See outline installation drawings

Table 15: Power System Specification

DC input 20 to 60 VDC external power supply

External Battery Pack 42 VDC (new), 28 VDC (depleted). Holds up to two 400 watt hour batteries

Transmit 16W @ 35V (1200kHz), 37W @ 35V (600kHz), 115W @ 35V (300kHz) 22W @ 48V (1200kHz), 60W @ 48V (600kHz), 190W @ 48V (300kHz)

10 Outline Installation Drawings The following drawings show the standard Workhorse Navigator dimen-sions and weights.

Table 16: Outline Installation Drawings Description Drawing #

300/600 kHz Navigator 3000/6000 meter 967-6003

300/600kHz Navigator 967-6004

1200kHz Navigator 967-6006

External Battery Case 967-6007

NOTE. If you are having difficulty reading the text on the Outline Installation drawings, please use the electronic documentation. The documentation CD allows you to zoom in and rotate the graphics.



967-6003 Sheet 1



967-6003 Sheet 2



967-6004 Sheet 1



967-6004 Sheet 2



967-6006 Sheet 1



967-6006 Sheet 2



967-6007



NOTES

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