icListen AF User Guide
© December, 2017
11
5
Processing 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.
