Teledyne Everywhereyoulook WAYFINDER User manual

Information included herein is controlled by the Export Administration Regulations
(EAR) and may require an export license, license exception or other approval from the
appropriate U.S. Government agency before being exported from the United States or
provided to any foreign person. Diversion contrary to U.S. law is prohibited.
WAYFINDER
DOPPLER VELOCITY LOG (DVL) GUIDE
P/N 95P-6001-00 (October 2020)
© 2020 Teledyne RD Instruments, Inc. All rights reserved.

Page ii
EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page.
TABLE OF CONTENTS
CHAPTER 1-OVERVIEW ......................................................................................................................................1
Setting up the Wayfinder System.................................................................................................................1
Software Installation ............................................................................................................................1
Power Overview ...................................................................................................................................2
Cable Wiring Diagram...........................................................................................................................2
Bench Test Setup..........................................................................................................................................2
Connecting to the Wayfinder .......................................................................................................................4
Testing the Wayfinder System .....................................................................................................................4
Caring for the Wayfinder System .................................................................................................................4
CHAPTER 2–SYSTEM INTEGRATION .......................................................................................................................5
Mechanical Integration Considerations .......................................................................................................5
Location on Centerline .........................................................................................................................5
Level Pitch & Roll..................................................................................................................................5
Beam Clearance ...................................................................................................................................6
Bottom Strike Protection .....................................................................................................................6
X Y Axis Alignment................................................................................................................................7
Wayfinder Instrument (X, Y, Z) Coordinates ..................................................................................8
Routing the Cable.................................................................................................................................9
Flow Noise/Cavitation ..........................................................................................................................9
Isolation Hardware...............................................................................................................................9
Electrical Integration Considerations ...........................................................................................................12
Grounding Recommendations .............................................................................................................12
Acoustic Integration Considerations ............................................................................................................13
Data and Timing Considerations ..................................................................................................................13
Data Screening .....................................................................................................................................13
Three-Beam Solution............................................................................................................................13
Ping Timing...........................................................................................................................................14
System Synchronization .......................................................................................................................14
Software Integration ............................................................................................................................14
Troubleshooting...........................................................................................................................................15
Communications Issues........................................................................................................................15
Identifying EMI .....................................................................................................................................15
Examples of Clean FFT Plots, No Interference ...............................................................................16
Examples of Interference ...............................................................................................................16
Unfavorable Environments ..................................................................................................................17
CHAPTER 3–USING WAYFINDER TOOLS .................................................................................................................18
Using the Wayfinder Tools app ....................................................................................................................18
Communication Settings ......................................................................................................................18
Dashboard Tab .....................................................................................................................................19
System Tab ...........................................................................................................................................20
Diagnostics Tab ....................................................................................................................................21
FFT Tab .................................................................................................................................................22
Tools Tab..............................................................................................................................................23
Setting the Wayfinder’s Real-Time Clock .......................................................................................23
Updating the Wayfinder’s Firmware..............................................................................................24
Enabling Wayfinder Features .........................................................................................................24
Setting the Wayfinder to the Factory Defaults ..............................................................................25
Changing the Wayfinder’s Baud Rate ............................................................................................25
CHAPTER 4-MAINTENANCE.................................................................................................................................26
Replaceable Parts.........................................................................................................................................26
Periodic Maintenance Items ........................................................................................................................26
Wayfinder Inspection ...........................................................................................................................26

Page iii
EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page.
Zinc Anode Inspection and Replacement .............................................................................................26
Removing Biofouling ............................................................................................................................27
Protective Coating Inspection ..............................................................................................................27
APPENDIX ANOTICE OF COMPLIANCE ....................................................................................................................28
Date of Manufacture....................................................................................................................................28
Environmental Friendly Use Period (EFUP) ..................................................................................................28
WEEE............................................................................................................................................................28
CE .................................................................................................................................................................29
Material Disclosure Table.............................................................................................................................29
LIST OF FIGURES
Figure 1. Wayfinder Overview...................................................................................................................1
Figure 2. Wiring Diagram Using the Recommended USB to Serial Adapter..............................................3
Figure 3. Wiring Diagram Using a DB9 Serial Connector ...........................................................................3
Figure 4. XYZ Instrument Velocities ..........................................................................................................8
Figure 5. Outline Installation Drawing –Wayfinder 600 kHz Sheet 1 ......................................................10
Figure 6. Outline Installation Drawing –Wayfinder 600 kHz Sheet 2 ......................................................11
LIST OF TABLES
Table 1. Wayfinder Power/Comm Cable Pigtail Wiring ...........................................................................2
Table 2. Wayfinder Mounting Checklist...................................................................................................5
Table 3. Transmit and Receive for the Wayfinder DVL ..........................................................................13
Table 4. Approximate Bottom Track Ping Times (in milliseconds) .........................................................14
Table 5. Wayfinder Replacement Parts..................................................................................................26
Table 6. Toxic or Hazardous Substances and Elements Contained in Product.......................................29
REVISION HISTORY
October 2020
•Initial Release.

Page iv
EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page.
HOW TO CONTACT TELEDYNE RD INSTRUMENTS
If you have technical issues or questions involving a specific application or deployment with your instru-
ment, contact our Field Service group:
Teledyne RD Instruments Teledyne RD Instruments Europe
14020 Stowe Drive
Poway, California 92064
2A Les Nertieres
5 Avenue Hector Pintus
06610 La Gaude, France
Phone [phone] Phone [phone]
Sales – [e-mail] Sales – [e-mail]
Field Service – [e-mail] Field Service – [e-mail]
Client Services Administration – [e-mail]
For all your customer service needs including our emergency 24/7 technical support, call [phone]
Wayfinder Product Website:
https://teledynerdi.myshopify.com/#Documentation

Wayfinder DVL Guide P/N 95P-6001-00 (October 2020)
EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page. Page 1
Chapter 1 - Overview
The Wayfinder assembly contains the ceramics and electronics with a molded one-meter serial cable. The
standard acoustic frequency is 600 kHz. See Figure 5 and Figure 6 for dimensions and weights.
Note that the urethane face covers the ceramics and provides a robust, flexible waterproof seal. Avoid set-
ting the Wayfinder on bumpy surfaces that may leave an indentation in the urethane or damage the ure-
thane face or anodized finish.
Figure 1. Wayfinder Overview
Setting up the Wayfinder System
Use this section to connect the Wayfinder to a computer and establish communi-
cations. Install the Wayfinder Tools software to communicate with the Wayfinder.
Where do I download the Wayfinder software and manual?
Wayfinder Product Website: https://teledynerdi.myshopify.com/#Documentation
Software Installation
The customer application for all core Wayfinder functionality is the Wayfinder Tools app. This software
runs on Windows and Linux.
To install the Wayfinder software:
1. Use the Wayfinder Product Website and download the Wayfinder Tools app.
2. Double-click on the Wayfinder Tools xx.xx setup.exe file (where xx.xx is the version number) to
install.
3. Use the desktop icon to start the app or click Start, Teledyne RD Instruments, Way-
finder_Tools.

P/N 95P-6001-00 (October 2020) Wayfinder DVL Guide
Page 2 EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page.
Power Overview
The Wayfinder requires a DC supply between 11.4 to 36.7 VDC (24 VDC typical). Either an external DC
power supply or battery can provide this power. The power supply should be able to source at least two
Amps.
Input Voltage Range Transmit Power Average Power Idle Power
11.4 to 36.7VDC 25 W 3.0 W 1.5 W
There is a constant background power consumption of 1.5 watt (idle power) anytime the Wayfinder is
powered and not pinging. The average power consumption depends upon the transmit duty cycle. As soon
as you connect to the system using Wayfinder Tools, the system begins pinging.
Cable Wiring Diagram
The following table shows the Wayfinder Power/Comm cable connections. Where shown, RX is the in-
coming signal; TX is the outgoing signal.
Table 1. Wayfinder Power/Comm Cable Pigtail Wiring
Wire Color Signal Wire Gauge
Red Power (+) 22AWG
Black Power Return (-) 22AWG
Brown COM_GND 22AWG
Orange RS-232_TX 22AWG
Yellow RS-232_RX 22AWG
Green Not Used N/A
Pigtail cable is one meter.
Cable bend radius is 10x cable diameter
Nominal cable O.D. is 0.247" to 0.263" Max. (6.2mm to 6.7mm Max.)
Jacket wall Nom. is 0.032" (0.81mm)
Cable bundle diameter is 0.228" (5.79mm)
The cable has foil shielding. It is not terminated inside the Wayfinder and can be grounded at
the cable end if needed.
Bench Test Setup
Several parts and tools are needed to setup the Wayfinder DVL for a bench test.
•USB to RS232 adapter (recommended). Source for purchase here.
or
DB9 female socket, solder cup. Source for purchase here.

Wayfinder DVL Guide P/N 95P-6001-00 (October 2020)
EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page. Page 3
•Laptop/tablet
TRDI recommends a medium to high-end model or Windows Surface tablet with Windows 10 or
Linux operating systems.
•Battery or power supply
Either an external DC power supply or battery can provide the 11.4 to 36.7 VDC (24 VDC typical)
power. Source for purchase here.
•Tools
Soldering iron, wire stripper (22AWG capable), heat shrink.
Figure 2. Wiring Diagram Using the Recommended USB to Serial Adapter
RS-232 RX and TX are from the perspective of the Wayfinder. Serial adapters or other
terminations may follow the opposite convention so the RX and TX connections may need to
be swapped.
Figure 3. Wiring Diagram Using a DB9 Serial Connector

P/N 95P-6001-00 (October 2020) Wayfinder DVL Guide
Page 4 EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page.
Connecting to the Wayfinder
To establish communications with the Wayfinder using the Wayfinder Tools app:
1. Connect the Wayfinder cable to the computer’s serial port.
2. Apply +12 to 36VDC power (24 VDC typical) power to the system.
3. Start the Wayfinder Tools app using the desktop shortcut.
4. Select the Port the cable is connected to and set the Baud
rate to 115200 (default setting).
5. Click the Connect button. As soon as you connect to the
system using Wayfinder Tools, the system begins pinging.
Testing the Wayfinder System
You should test the Wayfinder DVL:
•When you first receive the system.
•Before each deployment or every six months.
•When you suspect instrument problems.
•After each deployment.
To test the Wayfinder:
1. Connect the Wayfinder cable to the computer’s serial port.
2. Apply +12 to 36VDC power (24 VDC typical) power to the system.
3. Start the Wayfinder Tools app.
4. Click on the Diagnostics tab.
5. Click the Run tests button.
6. If all the tests pass, the Wayfinder is functioning normally.
7. If any of the result shows fail, contact TRDI Field Service for more information.
Caring for the Wayfinder System
This section contains a list of items to be aware of every time handling, using, or deploying the Wayfinder.
Please refer to this list often.
•Never set the Wayfinder on a hard or rough surface. This may leave an indentation in the ure-
thane, damage the urethane face, or scratch the anodized finish.
•Do not expose the Wayfinder to prolonged sunlight (24 hours or more). The urethane face may
develop cracks. Cover the Wayfinder if it will be exposed to sunlight.
•Do not store the Wayfinder in temperatures over 60 degrees C or under -25 degrees C. The inter-
nal components and/or urethane face may be damaged.
•Do not connect other metal to the Wayfinder. Other metals may cause corrosion damage. Isolat-
ing bushings must be used when mounting the Wayfinder to a metal structure.

Wayfinder DVL Guide P/N 95P-6001-00 (October 2020)
EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page. Page 5
Chapter 2 – System Integration
This chapter is intended to provide the necessary and often critical implementation and integration con-
siderations for the use of Wayfinder systems on various platform types. In addition, the procedures de-
scribed provide a step-by-step guide that will enable the client to configure the Wayfinder DVL sonar for
optimum utilization.
Mechanical Integration Considerations
Before choosing a mounting location, keep in mind the following mounting requirements.
Table 2. Wayfinder Mounting Checklist
Mounting Criteria Critical
Requirement
Vehicle
Dependent
Notes
Location on centerline Mechanically mount the center of the Wayfinder as close as
possible to the vehicle’s fore-to-aft centerline.
Level pitch/roll
Mount the Wayfinder as level as possible using the vehicle’s roll
and pitch references.
Beam clearance
Clear the Wayfinder beams of any acoustic obstacles. A 90-de-
gree cone around the face of the Wayfinder should be observed
to account for each beam acoustic spread.
Bottom strike protection
Ensure there is a section on the hull/platform that is lower than
the Wayfinder location to protect from bottom strikes.
X Y axis alignment Typical alignment is Beam 3 (instrument Y-axis) rotated 45° rela-
tive to the vehicle forward axis or Beam 3 facing forward.
Cable routing Tight mounting spaces next to bulkheads may require rotating
the Wayfinder to prevent sharp bends in the cable.
Flow noise/cavitation May need a fairing to reduce flow noise and/or cavitation.
Isolation Hardware
Use M5 isolating bushings and washers when mounting the
Wayfinder to a metal structure.
Location on Centerline
The mechanical alignment of the Wayfinder is important to data accuracy. Mechanically mount the center
of the Wayfinder as close as possible to the vehicle’s fore-to-aft centerline. Although it is preferable to
mount the Wayfinder on the centerline, other components or structural items may make this impossible.
Balance this requirement with the other critical requirements when choosing a mounting location. As dis-
tance from the centerline increases, accelerations caused by vessel rotation also increase. These accelera-
tions can cause additional uncertainties in Wayfinder velocity measurements.
Level Pitch & Roll
Mount the Wayfinder as aligned as possible with the vehicle’s frame of reference. Bottom Track only per-
forms up to around 15-degree tilt or slope (angle of incidence). To assure the best performance over slop-
ing bottom topography or system tilt, the system should be mounted as close to level as possible.
Significant misalignment in mounting may require post-processing to re-align the reference frames.

P/N 95P-6001-00 (October 2020) Wayfinder DVL Guide
Page 6 EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page.
Beam Clearance
Acoustic obstacles such as cables, hull, other in-
struments, etc. are numerous on undersea vehicles.
Special care should be observed in clearing the
Wayfinder beams of any acoustic obstacles. A 90-
degree cone around the face of the Wayfinder
should be observed to account for each beam
acoustic spread. Any acoustic obstacle in the Main
Beam and acoustic spread will interfere with the
Wayfinder measurement or worse prevent the
measurement altogether. If the Wayfinder is used
near a quay wall for instance, then a quick rule of
thumb is that for every meter of vertical separation
between the Wayfinder face and the seabed the
same separation is necessary between the Way-
finder and the Quay wall. The Wayfinder also has side lobes, which could collect energy backscattered by
acoustic obstacles in the beam clearance cone as shown in the outline installation drawing (Figure 5 and
Figure 6).
Bottom Strike Protection
When mounting the Wayfinder, ensure there is always a section on the hull/platform that is lower than
the Wayfinder location. This will reduce the risk of damage to the Wayfinder should you run aground or
collide with any submerged obstacle.
Good mounting location – on centerline, level pitch/roll. Wayfinder has good beam clearance
and is protected from the bottom and most submerged obstacles.

Wayfinder DVL Guide P/N 95P-6001-00 (October 2020)
EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page. Page 7
X Y Axis Alignment
TRDI recommends mounting the Wayfinder with the alignment line facing forward on the vessel. This
makes Beam 3 (instrument Y-axis) rotated 45° relative to the vehicle forward axis. This causes the magni-
tude of the signal in each beam to be about the same. This improves error rejection and increases the
Wayfinder’s effective velocity range by a factor of 1.4. Any significant misalignment in mounting may re-
quire post-processing to align the reference frames.
However, on some vehicles that operate at regular times close to vertical surfaces, it is desirable to mount
the Wayfinder with Beam 3 in-line to the vehicle axis. See Three-Beam Solution for more information.
For vehicles that routinely dive and raise in the water-column, it again may be desirable to mount the
Wayfinder with Beam 3 in-line to the vehicle axis so that as the vehicle pitches down and up, 15 to 20 de-
grees, at least 3 beams are tracking the bottom.
Note that tight mounting requirements next to bulkheads may require rotating the Wayfinder to prevent
sharp bends in the cable. See Routing the Cable for more information.

P/N 95P-6001-00 (October 2020) Wayfinder DVL Guide
Page 8 EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page.
Wayfinder Instrument (X, Y, Z) Coordinates
The Wayfinder uses Instrument Coordinates (X, Y, Z). Instrument Coordinate axis are always oriented the
same relative to the Wayfinder. Looking at the end view of the Wayfinder, the beams are labeled clockwise
in the order 3-2-4-1. When you look at the face of the Wayfinder, the beams are labeled clockwise in the
order, 3-1-4-2. The X-axis lies in the direction from Beam 1 towards Beam 2 and the Y-axis lies in the di-
rection from Beam 4 towards Beam 3. The Z-axis lies along the axes of symmetry of the four beams, point-
ing away from the water towards the housing.
The Wayfinder data format assumes the bottom is stationary and that the Wayfinder/vessel is moving.
•If Beam 3 is going forward, then the Y velocity is positive.
•If Beam 2 is going forward, then the X velocity is positive.
•If the bottom is going towards the face of a down facing Wayfinder, then Z is negative.
To compute the DVL physical forward and lateral velocity, rotate the XYZ Instrument Velocities by 45°.
Figure 4. XYZ Instrument Velocities

Wayfinder DVL Guide P/N 95P-6001-00 (October 2020)
EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page. Page 9
Routing the Cable
Use care when routing the Power/Comm 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 cables.
Route the cable so:
•Cable does not have kinks or sharp bends (see Cable Wiring Diagram for specifications). Tight
mounting requirements next to bulkheads may require rotating the Wayfinder to prevent sharp
bends in the cable.
•The Wayfinder cable (or junction box, if one is used) must NOT be exposed or installed next to
high voltage lines or circuits, motors or engines. See Identifying EMI for more information.
•If a junction box is used, make sure that all the cable conductors are connected properly and
avoid ground loop effects. Make sure that the conductors are electrically isolated from each
other.
Flow Noise/Cavitation
Water flowing over the Wayfinder face increases the acoustic noise level, which in turn decreases the op-
erational range of the Wayfinder. Flow noise can be reduced by mounting the Wayfinder behind a fairing.
Flow noise can also be reduced by optimizing the design to conform to the platform hull form being used.
Avoid mounting the Wayfinder DVL in the input or output area of a thruster as this will reduce the Way-
finder operating range AND thruster performance. Cavitation is the formation of air bubbles due to the
reduction of ambient pressure because of hydrodynamic flow conditions. Cavitation at the edges of the
Wayfinder or surrounding area near the Wayfinder often results in increased acoustic noise, and a corre-
sponding reduction in operating range. As with flow noise, cavitation can also be reduced by optimizing
the design to the platform hull form being used.
Isolation Hardware
Once you have chosen a mounting location, use the four M5 mounting holes on the housing. See Figure 5
and Figure 6 for dimensions and weights. The Wayfinder housing is made of aluminum that is protected
by a sacrificial anode and a hard anodize coat. Do not connect other metal to the Wayfinder as this may
cause corrosion damage. Isolation hardware is not required for use in freshwater environments; it is
strongly recommended to use M5 isolating bushings and washers for saltwater environments. Keep this in
mind when fabricating a fixture, which materials to use, or deciding how to place it on the vehicle.

P/N 95P-6001-00 (October 2020) Wayfinder DVL Guide
Page 10 EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page.
Figure 5. Outline Installation Drawing –Wayfinder 600 kHz Sheet 1

Wayfinder DVL Guide P/N 95P-6001-00 (October 2020)
EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page. Page 11
Figure 6. Outline Installation Drawing –Wayfinder 600 kHz Sheet 2

P/N 95P-6001-00 (October 2020) Wayfinder DVL Guide
Page 12 EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page.
Electrical Integration Considerations
Grounding Recommendations
The Wayfinder has three isolated grounds to achieve the desired performance levels of the instrument.
The grounding systems are as follows:
•Communication ground
•Power ground
•Chassis ground
Multiple grounds connected to a vehicle hull or to a vehicle chassis can have undesirable consequences.
Grounding problems can be avoided by implementing prudent grounding schemes.
The grounded systems noted above are isolated from each other. The Power Ground is isolated from the
Chassis Ground by an isolation / ground noise filter circuit. This ‘link’ between these two grounds is sus-
ceptible to EMI from outside sources if the isolation is not properly maintained outside the Wayfinder.
If the Wayfinder’s isolation / ground noise filter circuit is shorted, the Wayfinder may experience an in-
creased noise floor, ultimately propagating into the signal receivers.
This same isolation circuit will be shorted if the chassis (DVL GND) is in direct contact with the vehicle
chassis (vehicle GND) and the Power supply ground connected to the Wayfinder is also connected to
the vehicle chassis (vehicle GND).
The Wayfinder chassis is anodized, thereby providing electrical insulation when the instrument is
mounted into what are usually metal hulls. The anodized coating is required to maintain chassis ground
isolation.
Another potential electrical path bypassing the isolation/ground filter can occur through seawater. The
current generated can pass via the Wayfinder anode, (or scratches in the Wayfinder anodized coating),
through the seawater, and then back to the hull (or frame) to the vehicle. The likelihood of this ground
path occurring is increased if the hull of the vehicle is connected to the Power ground of the Wayfinder
through the vehicle’s grounding circuitry. Typically, this resistance is very high resulting in only a few mi-
croamperes of current and is limited by the size of the Wayfinder anode and the distance between the An-
ode and the grounded hull of the vehicle (the greater the separation the greater the resistance).
For the condition described, if the exposed surface resistance is great, the Wayfinder will not be adversely
affected, as is usually the case. For conditions where the surface resistance of the Wayfinder chassis and
vehicle are low, undesired interferences will occur.
Another way that you can have undesired grounding of the Wayfinder to the frame or hull of a vehicle
is that mounting holes can lose their anodized coating by scraping of the anodized inner wall with the
mounting screws. The use of an isolation plate and plastic bushings and washers are good practices to
avoid this grounding path.
In summary, bypassing or shorting the Wayfinder isolation / ground noise filter circuit will increase the
sensitivity of the Wayfinder to vehicle noise, which will increase noise floor in the instrument and in the
data, thereby resulting in a reduced operational range and data contamination from interference. Addi-
tionally, bypassing of the Wayfinder isolation/ground filter can lead to accelerated corrosion.

Wayfinder DVL Guide P/N 95P-6001-00 (October 2020)
EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page. Page 13
Acoustic Integration Considerations
Interference from other acoustic and electromagnetic devices can cause velocity and direction bias. In
extreme cases, interference may prevent the Wayfinder from operating. It is possible to avoid inter-
ference by using a suitable triggering scheme. This is particularly recommended if the other device is op-
erating within the bandwidth of the Wayfinder receiver (in some cases up to 40% of the carrier frequency
of the Wayfinder) or if the other device has a harmonic component that is within the Wayfinder fre-
quency receive bandwidth. Initiating a well-conceived triggering scheme (triggering the interfering de-
vice, the Wayfinder, or both) will keep the interfering device from operating during the Wayfinder’s
transmit and receive period. It is important to note that the TRDI receivers have 90 to 110 dB of
gain, which for the sake of clarity is greater than 100,000 times of voltage amplification.
Table 3. Transmit and Receive for the Wayfinder DVL
Wayfinder System Carrier Frequency Transmit & Receive Bandwidth
600 kHz 614400 Hz 38.4 kHz (6.25%)
Data and Timing Considerations
Data Screening
Wayfinder measurements suffer from occasional data outliers which, although rare, can still be far more
frequent that would be expected from a normal (Gaussian) probability function. To prevent the navigation
system from giving undue weight to data outliers, it is important to screen the Wayfinder data to detect
and reject them.
Data outliers are often the result of ambient data environmental factors. The Wayfinder DVLs have sev-
eral internal routines to detect and account for the false data described. Unless the bottom is detectable,
and the correlation value is above a threshold criterion, bottom track velocity will be marked Not a Num-
ber (NaN). The presence of fish in one or more beams will also cause data outliers. The Wayfinder also
screens for fish using the information in the intensity data for all four beams.
If all four beams pass these screening tests, the Error Velocity (representing the redundant information
among the four beam velocities) is calculated and its magnitude compared to a threshold as an additional
screen. Measurements exceeding this Error Velocity threshold will be rejected.
To keep the Wayfinder errors as independent as possible from ping to ping, the Wayfinder does not screen
for unreasonably abrupt changes in altitude or velocity. These kinds of screens are most appropriately
performed at the front end of a navigation system. An isolated abrupt change in altitude is most likely an
outlier (fish or other false target) that should be rejected, whereas a step function with a persistent final
altitude might be real (a cliff or a transition from a vehicle hull to the real bottom, for example). A robust
algorithm will reject the isolated data outlier while quickly recovering from a persistent step. Similar
screening can be done on velocities.
Three-Beam Solution
The Wayfinder screens the velocity data by comparing the magnitude of the Error Velocity to a threshold.
The Error Velocity has redundant information among the four beam velocities. A three-beam solution is
produced if, on a particular ping, only three beams have good data, and in that case only, error velocity
screening cannot be performed. The Wayfinder still computes a four-beam solution with error velocity
screening on all pings where all four beams have good data. There are operating circumstances where due
to the bottom slope and/or pitch only three beams can have adequate reflection from the bottom, while
the fourth beam is not. The three-beam solution makes it possible to operate in such severe environments.

P/N 95P-6001-00 (October 2020) Wayfinder DVL Guide
Page 14 EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page.
Ping Timing
It is usually desirable to minimize the time it takes a Wayfinder to complete a ping cycle because this ena-
bles faster data update rates. When the maximum operating altitude is known, the Max Range setting on
the System tab can be used to limit the maximum ping time in Bottom Track mode, since time to receive
data from the bottom is proportional to the distance to the bottom.
For example, if you know the maximum depth in the deployment area is 40 meters, set the value slightly
larger than 40 m, say 45 m, instead of default 60 meters. Now if the Wayfinder loses track of the bottom,
it will stop searching for the bottom at 45 m rather than spend time searching down to 60 m.
Table 4 shows the approximate Bottom Track ping times for a Wayfinder DVL as a function of altitude
above the bottom.
Table 4. Approximate Bottom Track Ping Times (in milliseconds)
Altitude in meters
Ping Time in ms
5
55
The following equation provides an estimate for the time between pings for ranges greater than 3.8m for
the Wayfinder:
Ping time (seconds) = RTB(m)*.42e-3+ 30e-3
Where RTB is the Range to Bottom in meters.
System Synchronization
Typically, data from the Wayfinder is fed into a larger user supplied acquisition and control system, which
collects data from other sources as well. In such situations, it is important to have all the data accurately
referenced to a common time base.
The Wayfinder data ensembles contain a time stamp with a 10 ms resolution from a reading of the real-
time clock before the ping, but the resolution in setting the time is limited to 1 second. If higher accuracy
is required, it is recommended to send the time set command using binary command or the python driver
at or near the full second.
Software Integration
The Wayfinder Tools software provides a graphical user interface for use with a Wayfinder DVL. It is a Py-
thon-based application, so it runs on a variety of operating systems including Windows and Linux and can
be executed directly on the platform.
To facilitate vehicle integration, there is an interface driver also in Python. This driver integrates directly
with many vehicles or top-side computer systems and provides the tools to configure and extract data
from the Wayfinder DVL.
Integration Steps:
1. Ensure remote access to host computer and internet access.
2. Install Python 3.6 (or later) on the host computer.
3. Install pyserial and numpy via pip for Python 3 on the host computer.
4. Use the WayFinder Python API to access the streamed data or send commands.
Notes:
•Confidence value for Wayfinder data is not available from the Python API
•Data timestamp can be up to 1 second off (see Setting the Wayfinder’s Real-Time Clock)

Wayfinder DVL Guide P/N 95P-6001-00 (October 2020)
EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page. Page 15
Troubleshooting
The purpose of this section is to provide a list of critical tests to perform when the system is not operating
to either specifications or expectations.
Communications Issues
The Wayfinder is connected to the data collection computer via a standard RS-232 serial port. If you have
problems communicating with the Wayfinder, check to make sure that you are selecting the correct serial
port or correct serial device. USB-serial adapters may be used if the computer does not have a serial port.
Be aware that some USB-serial adapters are not fully compatible with Wayfinder data collection. If you
experience communications issues with the USB-serial adapter, first try a different device. TRDI has had
good experience with the Edgeport®line of multi-port USB-serial adapters and single-port adapters using
the FTDI chipset and drivers.
Identifying EMI
The main sources of EMI are induced voltages from signal and power lines that are in proximity to the ef-
fected component or signal. These problems are avoided or minimized by the proper routing of wires,
proper shielding of wires and proper location of individual systems components. EMI is also caused by
unwanted differences in potential on signal or ground electronic lines.
It is critical to route the Wayfinder cable such that it is not in proximity to interfering signal sources, such
as clocks, CPU’s, DC-DC converters, engine controls, and hydroelectric power units, power lines, acoustic
devices and their power electronic. In the case of radiated EMI to the cable, then the EMI can be rapidly
reduced as the power reduction goes by square of the separation distance between the source and the
Wayfinder cable.
To avoid problems when the Wayfinder is installed in the final system, it is helpful to perform a bench test
prior to installation. In the bench test, the Wayfinder should be exercised along with all the other compo-
nents that will be installed in the final system. By performing this initial bench test, EMI and acoustic in-
terference issues can be identified and remedied while all the system components are easily accessible.
The recommended types of systems that should be bench tested:
•If possible, select components and systems that are acoustically, and RF wise “out of band”,
based on the specifications from the manufacturer of that equipment.
•It is important to test for all EMI interference that may be occurring in the system. Bench test all
the equipment in air and see if there are interfering sources.
•Spread out the various systems and components that you intend to use on the bench in a pattern
similar to how they will work.
•Try varying bench test temperatures, so it can be determined if there are tank circuits in your
system that “tunes into” Wayfinder’s band, or visa-versa.
Observation of the FFT acoustic interference plots will provide information about interference to the Way-
finder DVL. The Wayfinder Tools app provides the user with a frequency domain plot (~100% band-
width) of the Wayfinder’s four receiver channels during a sampling interval.
To view the FFT data:
1. Start Wayfinder Tools and connect to the Wayfinder DVL.
2. Click on the FFT tab.
3. While observing the FFT use the Wayfinder as a “probe” and touch it against components or sys-
tems to check their acoustic signature. Identify any unacceptable interference. Observe changes in
the plots. Interference will show as large spikes.

P/N 95P-6001-00 (October 2020) Wayfinder DVL Guide
Page 16 EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page.
For example, separating devices or shielding may be help. Note that the Wayfinder face
(where the urethane is on the Wayfinder) will always be submerged in water during real opera-
tion. You can simulate this in water performance by placing the Wayfinder at the bottom of a
small bucket, with just enough water to wet the urethane faces. Often what appears to be inter-
ference when the Wayfinder is in air may be completely gone when the Wayfinder is submerged in
water. The inverse may be true as well. If there are other sonars or mechanical devices such as hy-
draulic power units that create acoustic signals, these may interfere with the Wayfinder system
and the interference may only be detected when both the Wayfinder and the other device are
submerged in a larger bucket or tank of water or somehow acoustically coupled through a hull or
structural framework.
Examples of Clean FFT Plots, No Interference
The following is a screen shot of a typical “clean” FFT.
Examples of Interference
The following image shows an interference term on all channels at 619.95 kHz just to the right of center
frequency.
Although not ideal, the previous interfering terms is small, and the Wayfinder will still bottom track accu-
rately if the bottom echo return amplitude is stronger than this very weak interfering term.
The following types of interference will have significant effects on the accuracy of bottom track.