0) and the noise level at the time of the detection. Fields Info3 and Info4 are not used in
detection reports. The second report type is an effort report which has a type of 'E'. The
effort report indicates the times over which the detector was operating. There will usually
be an on-effort report at the start of each recording (i.e., with a detector state of 1) and an
off-effort report at the end of each recording. The on-effort report has no other data and so
appears as:
seconds,microseconds,E,1,,,
The off-effort report appears as:
seconds,microseconds,E,0,noise level,ndets,nsaved,
where ndets is the total number of detections made since going on effort and nsaved is the
number of these for which snippets were saved. In both report types, the noise level is given
in Centibels, i.e., 100 log10(p) where p is the noise power referenced to the recorder
calibration. The absolute threshold used for each detection is then p+10^(RDT/10). If no
detections were made throughout a recording, the BCL file will contain two lines:
start_time,microseconds,E,1,,,
end_time,microseconds,E,0,noise level,0,0
If there are detections, they will be bracketed between these lines and the appropriate
detections counts will be changed in the off-effort report. The BCL file can be read and
displayed by Excel, Libre Office, Open Office etc. See also the Matlab tools for a function to
read this file format.
4.1.5
Click Detector Caveats and Cautions
While every care has been taken in producing the SoundTrap Click Detector, this is free software
offered
‘
as is
’,
in the hope that it will be useful: there is no warranty, implied or otherwise, nor
implication of fitness for any particular purpose. Please use responsibly! Test that the code functions
correctly on your SoundTrap before deploying it, e.g., by setting the RDT to 12 dB and then tapping
lightly on the hydrophone with a finger nail. Even if the code is functioning, it may not detect clicks
because of poor signal-to-noise ratio, because of inappropriate user settings, or because of a poor
mooring design (the same problems that would give you a bad continuous recording). Where using
settings other than defaults, it is strongly recommended to do a pilot deployment to validate
settings perform as expected.
