Transcript Development of a long range pinger Test device

Development of a long range pinger Test device
Background:
The council Regulation EC No 812/2004 details the mandatory use of
acustic deterrent devices to deter Cetaceans from bottom set gillnet
and entangling net.
The German authorities wanted to have a pinger control device that
allows the counting control of functioning pinger on a setnet without
the fishermen being at the place and retrieving the nets.
The device should allow:
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to identify the Pinger signal (analog and digital sound)
to conduct a pinger function test at sea and in a bucket
to count the number of pinger fitted on the net at sea
to measure the distance between individual pingers with the
additional help of a hand-held GPS
Tested Pinger types and specifications
Pinger
type
AquaMark
100
Airmar
Gillnet
Pinger
Fumunda
Sound
Level
(db)
145
132
132
Frequency
(khz)
20-160
10
10
Signaltype
Repetion
Analogue/
Rate (s)
Digital
D/
broadband
sweep
A/tone
A/tone
Remarks
4-30
increasing and
decreasing
frequencies
(200m spacing)
4
constant
frequency
(100m spacing)
4
constant
frequency
(100m spacing)
Prototype and final version of the pinger control device
PG 1101 Ping Go (ETEC )
 equipped with a sensitive
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hydrophone TC4033 (RESON)
LEDs are optical indicator for
ultrasound frequencies received
close-by
equipped with 3 operating modes
and 4 noise filters
allow recording all signals
convert ultra sound signals into
audiable frequencies
amplify original hydrophone signals
mix both modes
filter can reduce low fequencies of
background noice e.g. coming from
vessel engines.
make it possible to detect pingers
aboard
Results of field tests
• Depending on the actual weather and sea conditions the analog
Pinger signals can be detected up to 900 m and up to 400 m for the
digital sweep signals when listen on a rubber boat or in the harbor.
• Listen aboard the Dänish inspektion vessel „Harvörnen“ the
detection will be also possible when the main engine is stopped, but
at a lower range
• From our research cutter „Clupea“ it was able to detect both pinger
signals at a distance of 220 m with engine switched to idling speed.
• The optical indicaters (LEDs) for the detected frequency was
functioning up to a distance of 50 m.
The instrument is not only interesting for fishery inspection
purposes but also for wale watching. A simplified, cheaper version
for fishermen is advertised.