Ocean Sonics icListen AF User manual

icListen AF User Guide
December 11, 2017
icListen AF Smart Hydrophones
Ocean Sonics Ltd.
Hill House, 11 Lornevale Road,
Great Village, NS, B0M 1L0 Canada
Phone: [phone]
www.OceanSonics.com

icListen AF User Guide © December, 2017i
Table of Contents
Table of Contents........................................................................................................................................... i
Table of Figures............................................................................................................................................ iv
1 icListen Smart Hydrophones .................................................................................................................5
2 Features of icListen AF..........................................................................................................................6
2.1 AF –Feature Summary..................................................................................................................7
3 Quick Start –Bench Setup.....................................................................................................................8
3.1 Checklist........................................................................................................................................ 8
3.2 Steps.............................................................................................................................................. 8
4 Ocean Sonics’ LucyTM Software...........................................................................................................10
5 Processing in icListen ..........................................................................................................................11
5.1 Waveform (Time Domain) Data..................................................................................................11
5.1.1 Real-Time Data....................................................................................................................11
5.1.2 Stored WAV Data ................................................................................................................11
5.1.3 Gain .....................................................................................................................................12
5.1.4 Duty Cycling.........................................................................................................................12
5.2 Power Spectrum (FFT) Data ........................................................................................................13
5.2.1 Real-time Data ....................................................................................................................13
5.2.2 Stored FFT Data...................................................................................................................13
5.2.3 Windowing..........................................................................................................................13
5.2.4 FFT Processing Options .......................................................................................................14
5.3 Epoch Mode ................................................................................................................................16
5.4 Logging Start Time ......................................................................................................................17
6 Additional Features of icListen............................................................................................................18
6.1 Temperature and Humidity ........................................................................................................18
6.2 Acceleration and Magnetic Field ................................................................................................18
6.3 Battery Monitoring .....................................................................................................................18
6.4 Wake From Standby....................................................................................................................19

icListen AF User Guide © December, 2017ii
6.5 Buzzer Patterns ...........................................................................................................................19
6.6 Time Synchronization..................................................................................................................19
6.7 Network Discovery......................................................................................................................20
6.8 Low Power -12V Operation.........................................................................................................20
7 Logged Data Retrieval.........................................................................................................................21
8 Standard Operation Procedures (SOPs)..............................................................................................22
8.1 Autonomous Data Logger Deployment ......................................................................................23
8.2 Autonomous Data Logger Data Recovery...................................................................................24
9 Care and Maintenance........................................................................................................................25
9.1 Firmware Updates.......................................................................................................................25
9.1.1 Firmware Update Using Lucy ..............................................................................................25
9.1.2 Firmware Update Using an FTP Client and Internet Browser.............................................26
9.2 File System Care..........................................................................................................................26
9.3 Connector Care ...........................................................................................................................27
9.4 Retrieval and Storage..................................................................................................................27
9.5 Long Term Storage......................................................................................................................28
9.6 Deployment.................................................................................................................................28
9.7 Long Term Deployment ..............................................................................................................28
10 Troubleshooting icListen.....................................................................................................................29
10.1 Instrument not communicating..................................................................................................29
10.2 I need to find out the icListen firmware version and serial number ..........................................29
10.3 The information displayed on the web interface is blank or not updating ................................29
10.4 I’m starting to miss data in my icListen WAV logs ......................................................................29
10.5 I can’t connect to my Ethernet icListen’s IP address ..................................................................30
10.6 The battery charge drops dramatically when using the Reverse Bias Plug ................................30
11 FAQ - Frequently Asked Questions .....................................................................................................31
11.1 What happens when the icListen’s internal memory fills during logging?.................................31
11.2 What is the login/password/port for SFTP and SCP?..................................................................31
11.3 Why are the values in the low frequency bins of my spectrum data so low?............................31
12 Options and Configurations ................................................................................................................32

icListen AF User Guide © December, 2017iii
13 Wiring Tables for icListen....................................................................................................................33
13.1 icListen Ethernet Interface..........................................................................................................33
13.2 Ethernet Cable ............................................................................................................................34
13.3 icListen Serial Interface...............................................................................................................35
13.4 Shorting Jumper..........................................................................................................................35
14 Recommended Connectors.................................................................................................................36

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Table of Figures
Figure 2-1: icListen AF...................................................................................................................................6
Figure 3-1: Lucy Ethernet connection display...............................................................................................8
Figure 3-2 : Lucy status display .....................................................................................................................9
Figure 3-3: Lucy example display ..................................................................................................................9
Figure 4-1: Lucy main display......................................................................................................................10
Figure 5-1: FFT’s with 0% Overlap...............................................................................................................14
Figure 5-2: FFT’s with 50% Overlap.............................................................................................................14
Figure 5-3: Epoch Triggers ..........................................................................................................................16
Figure 10-1: Lucy status bar........................................................................................................................29
Figure 13-1: Subconn MCBH8M male face .................................................................................................33
Figure 13-2: Subconn MCIL8F female face .................................................................................................34
Figure 13-3: RJ-45 Pin positions..................................................................................................................34
Figure 13-4: Subconn MCBH8M male face .................................................................................................35
Figure 13-5: Subconn MCDC8F female face................................................................................................35
Figure 14-1: Subconn MCBH8M male face .................................................................................................36

icListen AF User Guide © December, 20175
1icListen Smart Hydrophones
The concept of the icListen Smart Hydrophone has been in development since 2005. Smart
Hydrophones take the work out of gathering acoustic data in the ocean. They supply data in real units,
processing it as needed before it is stored or sent to the operator.
These hydrophones are ideal for a range of passive acoustic applications, such as:
•Environmental assessments of underwater acoustic noise
•Monitoring for marine life, including sea mammals and spawning fish
•Laboratory reference hydrophone
•Locating sound sources, such as malfunctioning equipment, or flight data recorders
•Locating leaks in underwater pipes, and identifying machine noises
Users communicate with icListen through a PC program called Lucy, or using the web interface. Lucy
allows users to view instrument data in real-time, retrieve and play stored data, and perform
housekeeping functions, such as checking the status & configuration. Ethernet icListen models contain a
web interface which can be used for device configuration and for viewing real-time spectral data.
We hope you enjoy your experience with icListen AF, and look forward to receiving your feedback.

icListen AF User Guide © December, 20176
2Features of icListen AF
The icListen AF combines high signal integrity, data storage capacity, low power and small size with the
ability to process sound data in real-time.
The icListen AF can be used in a tethered mode, or as an acoustic data logger.
In tethered mode, real-time waveform or spectral data can be
continuously streamed to a host PC running the Lucy program.
As a data logger, icListen AF can be configured using Lucy or its web
interface, then left for extended periods under water to collect
waveform or spectral data, storing it internally.
The amount of recording time is dependent upon the sample rate,
as seen in the following table.
Figure 2-1: icListen AF
How Sample Rate Affects Storage Time
Sample Rate
24 Bit Data
16 Bit Data
GB per day
Days with 256 GB
GB per day
Days with 256 GB
1 kS/sec
0.61
417
.53
480
2 kS/sec
0.87
292
.7
363
4 kS/sec
1.4
181
1.0
254
8 kS/sec
2.4
106
1.7
149
16 kS/sec
4.5
56
3.1
82
32 kS/sec
8.6
29
5.9
43
*GB per day values are calculated based on logging 1 minute wav files
Note that storage time can be increased significantly by: enabling Duty Cycle Logging to record data
periodically, logging based on epoch triggers rather than logging continuously, or by storing processed
power spectrum data instead of waveform data.
Waveform data is logged in the standard “.wav” format, making it accessible from a wide range of
software programs. Spectral data is in a tab-separated .txt format, suitable for spreadsheet viewing. See
the icListen Log File Formats document for more detailed descriptions of the log files. The Lucy program
is ideal for viewing stored waveform or spectral data.
Spectral analysis of data is optionally performed in the instrument, and can be averaged for up to one
minute to reduce the quantity of data transferred or stored.

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2.1 AF –Feature Summary
•Frequency Range: 10 Hz - 10 kHz (1Hz - 10kHz option is available)
•Low power, approximately 2 W
•Battery Life: 8+ hours (operating), 4+ days (standby)
•Power input (with internal battery), 24 VDC +/-25%
•Power input (without internal battery), 12 VDC +/-20%2
•Supplies real-time waveform and processed data, in tethered mode
•Processed data in tab separated spreadsheet .TXT format
•Waveform data in WAV format, with meta data stored in file header
•256GB of internal storage capacity2
•Event detection, up to 5 bandwidth configurable triggers
•Monitors internal temperature and humidity
•Monitors battery charge state
•Indicates startup/shutdown through buzzer patterns
•Seconds can be aligned to falling edge of PPS
•Time of day can be synchronized through messages encoded in PPS
•Interfaces –Ethernet, Serial RS232/RS422
•Maximum depth: 3500 meters
•Size: 48 mm dia., 267 mm long
•Depth rating: 200 or 3500 meters
1Available as of hardware rev 5
2icListen AF previously shipped with 128GB and 32GB of internal storage

icListen AF User Guide © December, 20178
3Quick Start –Bench Setup
It is important to test icListen when it is first unpacked and before each deployment, for best results.
The hydrophone works in air well enough to provide a good functional test. Arrange a work surface large
enough to hold the hydrophone, cables and the PC used to run the Lucy software.
3.1 Checklist
1. Hydrophone to be tested (note its serial number).
2. A PC (ideally the same portable one used to deploy the hydrophone), with the Lucy software
already installed. Ensure the PC has a suitable data port interface for the icListen instrument.
3.2 Steps
1. Connect the icListen to the link cable, and the data link to the PC.
2. Start up the Lucy program on the PC.
3. Click the icListen Setup button in the lower right. In the popup window, select the Link tab and
chose the appropriate connection type. To find your icListen, click “Find All Units”. To connect,
double click the unit from the found units list.
Figure 3-1: Lucy Ethernet connection display

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4. Click the ‘Enquire’ button in the middle top of the display. A message to the right will display if
the enquire was successful. Note the serial number in the displayed message, to ensure it
matches the number on the hydrophone. The message also displays the sensor temperature
(which may be slightly different from that outside the instrument), the internal humidity, and
the battery charge state.
Figure 3-2 : Lucy status display
5. The humidity is an indication of the seal quality. A humidity reading of 50% or less is acceptable.
Higher readings indicate a possible leak in the seal. Contact Ocean Sonics if the humidity is
higher than 80%. Close the Setup window if it is still open.
6. Click the ‘Start’ button in the top left corner. The display should begin to show data in the
charts. Gently tap the hydrophone, or whistle near it, to cause a change in the display. If the
display is black/red, change the reference setting on the bottom left until blue or green is
visible.
7. If a changing data display is seen, the hydrophone is ready to put in the water. Events will show
up on the display approximately 1 second after they have occurred. See the following display for
an example.
Figure 3-3: Lucy example display

icListen AF User Guide © December, 201710
4Ocean Sonics’ LucyTM Software
The PC software used to talk to the icListen hydrophones is called Lucy. It presents data to the operator
in a graphical and numerical format.
Lucy allows a user to fully configure, monitor status, and retrieve live and logged data from icListen. It is
also capable of logging live data as it is retrieved and later viewing and analyzing logs created either by
icListen or Lucy.
The interaction of the software has been designed for field operations personnel, making it simple to
use once configured.
Figure 4-1: Lucy main display
Please refer to the Lucy User’s Guide for instructions on operating the Lucy software.

icListen AF User Guide © December, 201711
5Processing in icListen
One thing that makes icListen hydrophones smart is their ability to process data. Several types of
processing are available to icListen devices, all of which add value to the data.
icListen is capable of transmitting real-time waveform data, and storing this data for later analysis. All
icListen smart hydrophones can also convert incoming data to power spectrum frequency data. This
data can be processed in different ways, transmitted in real-time, stored, or used to trigger various
effects in Epoch mode. In icListen AF, waveform and spectrum data can be streamed, logged, or
collected through the command and control channel. Data cannot be streamed and logged
simultaneously (but can be collected from the command and control channel while logging).
5.1 Waveform (Time Domain) Data
Waveform data represents the raw signal detected by a hydrophone. Acoustic data is converted from
analog to digital, where it can then be processed by icListen.
5.1.1 Real-Time Data
icListen AF is capable of transmitting real-time waveform data to users, using software such as Lucy.
Along with the digital waveform data, icListen will also transmit information on how the unit was
configured when the data was collected, which can be used to convert the received numbers to voltage
or pressure measurements.
5.1.2 Stored WAV Data
Waveform data may also be stored by icListen AF in standard uncompressed WAV files. This makes data
recorded by icListen readable by many third-party sound editing programs and analysis tools, as well as
by Ocean Sonics’ Lucy software.
In addition to the waveform data, icListen will store additional metadata in the WAV file’s LIST chunk,
which can prove to be useful for analysis. For more information on the WAV file format, and the
additional information provided in the LIST chunk, please refer to the icListen Log File Formats
document.
Data can be retrieved using the web interface or through FTP, SFTP, and SCP using an FTP client such as
FileZilla. Data may also be retrieved from Ethernet units using Lucy. For SFTP and SCP, the username is
“icListen”, the port is 22, and by default there is no password. FTP requires no user name or password.

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5.1.3 Gain
In icListen AF, gain may optionally be applied to 16-bit waveform data. Applying gain affects the
dynamic range of the instrument, by increasing the minimum amplitude signal which can be detected by
an instrument, and decreasing the maximum amplitude signal which can be measured by the
instrument. This behavior makes increasing gain desirable in quiet environments where important
information could be otherwise lost, but undesirable in loud environments where data would be lost
due to “clipping” of the signal if gain were applied.
icListen AF samples waveform data at 24bits, and makes use of gain to allow access to the low 8bits of
data which would otherwise be lost when returning only 16bits.
5.1.4 Duty Cycling
When storing waveform data, icListen AF can also perform duty cycling, to reduce the amount of data
logged internally. The cycle length, and active portion of the duty cycle can be configured with 1 minute
resolution, and the first active phase of logging will begin when the configured start time has been
reached.

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5.2 Power Spectrum (FFT) Data
One of the most powerful processing features of icListen smart hydrophones is their ability to provide
power spectrum frequency data. Looking at data in the frequency domain, rather than the time domain,
provides a clearer picture of what’s going on within a sound, and can dramatically reduce the storage
and bandwidth requirements of an operation.
5.2.1 Real-time Data
All icListen models are capable of providing real-time frequency data. This data provides a clear picture
of what’s happening in a sound. Transmitting frequency data rather than waveform data reduces the
bandwidth requirement dramatically as well, which saves on transmission costs, and improves reliability.
This data is also accompanied by information on how the unit was configured when the data was
collected, as well as scaling information which can be used to convert the data to voltage or pressure
measurements.
5.2.2 Stored FFT Data
icListen AF is capable of storing processed power spectrum data in tab-separated values format TXT
files. These files can be read by virtually any spreadsheet or text editor program.
Storing spectrum data can provide a much more compact form of data storage than waveform data,
allowing for faster data retrieval and analysis, and means that the unit can store data for longer periods
of time between data retrievals.
These files also store additional sensor data (such as temperature and humidity), hardware information,
and setup information, which can be used to aid in analysis. For a more in depth discussion on the TXT
file format, please refer to the icListen Log File Formats document.
Data can be retrieved using the web interface or through FTP, SFTP, or SCP, using an FTP client such as
FileZilla. Data may also be retrieved from Ethernet units using Lucy. For SCP and SFTP, the username is
“icListen”, the port is 22, and by default there is no password. FTP requires no user name or password.
5.2.3 Windowing
icListen makes use of the Hann window function in order to reduce spectral leakage, when converting
data from time to frequency domain.

icListen AF User Guide © December, 201714
5.2.4 FFT Processing Options
Not all applications require data to be processed in the same way. For this reason icListen has been
designed to allow multiple options for power spectrum data processing.
5.2.4.1 Overlap
It is often useful to have some overlap in the waveform data used to compute frequency data. This helps
to improve the time resolution of the resulting data, and assists in ensuring we do not miss data that
may otherwise be filtered out by the Hann windowing operation. The figures below show an example
waveform data set, divided into sections which are used to compute frequency data. These figures show
the data used with no overlap (0%) and 50% overlap. icListen AF uses a 50% overlap for all spectrum
data.
Figure 5-1: FFT’s with 0% Overlap
Figure 5-2: FFT’s with 50% Overlap

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5.2.4.2 Mean Average
This form of processing will calculate the mean average power found at each frequency, over a
configurable averaging period. The averaging period is the number of FFT data sets over which the
average is calculated. This is the default type of processing used by icListen.
The mean value for each frequency bin is calculated as follows:




Where:
N= Averaging Period
Yi2= Signal Power of frequency bin
Ci,j = FFT Coefficient
i= Frequency Bin Number
j= FFT Data Set Number
5.2.4.3 Peak Value Detect
Peak value detect processing keeps track of the maximum power level found at each frequency. This is
done over a configurable number of FFT data sets. This type of processing is useful when looking for
events of a very short duration (such as pile driving, or leak detection).
5.2.4.4 Filtered
This form of processing performs infinite impulse response (IIR) filtering on the power levels detected at
each frequency. The type of filter used is an exponential moving average. The weighting of the average,
as well as how frequently the icListen will transmit results are both configurable in this mode. This has
the effect of smoothing new data with the previous FFT results.
The filtered data for each frequency is calculated as follows:
󰇛  󰇜

Where:
N= Weighting Factor
Yi,j2= Signal Power of frequency bin
Ci,j = FFT Coefficient
i= Frequency Bin Number
j= FFT Data Set Number

icListen AF User Guide © December, 201716
5.3 Epoch Mode
In Epoch mode, icListen can be configured to detect specific signals in the real-time spectrum data, and
perform a number of tasks based on those signals. icListen can check the data for 5 independent
triggers, each with a unique trigger signal and unique actions based on that signal.
Figure 5-3: Epoch Triggers
When setting up epoch triggers, both the trigger signal (event) and effect of detection can be
configured.
The trigger signal is defined by a frequency range to check, the type of test to perform (signal power
above or below a configured threshold), and the minimum duration the signal must be present.
The effect can be any combination of the following actions:
•Log waveform data
•Log spectrum data
•Transmit a message over the epoch channel
Logging events will be recorded for a configurable pre-event duration before the event signal was
present, during the event, and for a configurable post-event duration after the signal has gone away.
See the above figure for more detail.
Epoch messages will be sent when an event trigger signal has been verified (end of “Trigger” seen in the
above figure). Detection of the next trigger event will not begin until the post-event duration has
elapsed (and therefore no new messages will be sent for this trigger during this time). All streamed
epoch messages are also logged internally on the instrument.

icListen AF User Guide © December, 201717
5.4 Logging Start Time
icListen AF can be configured to start logging data at a specific date/time. Configuring a start time allows
a deployment to be set up well in advance of an actual testing/monitoring session, without unwanted
data being logged during this time. Until the start time has been reached, no waveform (WAV files) or
frequency spectrum (TXT files) will be logged, but live data can still be transmitted from the instrument.

icListen AF User Guide © December, 201718
6Additional Features of icListen
icListen also contains some additional features that can aid with troubleshooting, deployment, and
operation of the device.
These features include: monitoring temperature, humidity, acceleration and magnetic field, measuring
battery charge state, wake from standby, producing buzzer patterns to indicate power up/down, time
sync, and network device discovery options for Ethernet icListen devices.
6.1 Temperature and Humidity
Temperature and humidity values are continuously measured internally in all icListen models.
The internal temperature of an icListen will generally be slightly warmer than the outside temperature
(more so when the unit is out of water). It is useful for determining if any temperature shocks are
experienced during testing. Rapid changes in temperature can result in a DC offset being introduced to
waveform data. In some cases the offset can be great enough to “clip”/”max out” the data. This effect is
expected and temporary, and knowing the temperature changes that the device experienced can help in
determining if this is occurring.
The relative humidity reading can be used to determine the seal quality of the instrument. A humidity
reading of 50% or lower is acceptable. If the reading is higher than this, it may indicate a leak in the seal.
6.2 Acceleration and Magnetic Field
Accelerometer and magnetometer readings are available for icListen AF. These values can be used to
monitor changes in the orientation of the instrument once it has been deployed.
6.3 Battery Monitoring
icListen AF monitors the charge and state of the internal battery. This allows a user both to know when
the batteries have been fully charged, estimate how long the icListen will run from the internal battery,
and can be used to determine if there are any issues with the battery.
Note that the battery may not charge when the battery voltage is above 4V (approximately 90%). This is
normal behavior, and is done in order to prevent premature aging of the battery.
During normal operation the battery life of the instrument should be 8 or more hours, and when in
standby should be 4 or more days.

icListen AF User Guide © December, 201719
6.4 Wake From Standby
icListen can be configured to wake from standby mode without applying external power. If this feature
is activated, icListen will wake from standby when the shorting plug is attached, or when the auxiliary
(sync) line is driven low. icListen will not wake if the battery level is too low for stable operation. Note
that a fully charged icListen has a battery life of 4+ days when left in standby mode.
6.5 Buzzer Patterns
icListen AF contains a buzzer motor to indicate status of the unit. The buzzer patterns can be used to
ensure that the device is functioning as expected. The patterns produced by icListen are given in the
following table:
Buzzer Patterns used by icListen
Pattern Meaning
Pattern
Unit Booting Up
1 short pulse (0.5s)
Firmware is Ready/Running
2 short pulses (0.5s each)
Unit Shutting Down
3 short pulses (0.5s each)
Error Booting Unit
1 short & 1 long pulse (0.5s and 1s), repeated 3x
*Note that the error pattern may repeat multiple times if unit is unable to boot
*Any patterns not listed in this table may be the result of patterns being prematurely cut off
by low battery charge
6.6 Time Synchronization
icListen AF can be configured to synchronize its time of day to other icListen devices by
encoding/decoding the time of day within a pulse per second (PPS). When using this feature, one
icListen device should be set as the master (encode time), and all other connected icListen devices
should act as slaves (decode time). This same PPS signal is used to precisely align the samples collected
by all connected icListen units.
icListen AF is also capable of having its time of day set over the command & control connection to the
device. This can be done using Ocean Sonics’ Lucy software or using the web interface, to synchronize to
the time on your PC. This method can be used to set the time of day on the master icListen device when
synchronizing multiple units together.