Towed PAM Systems
Our flagship Passive Acoustic Monitoring system is extensively deployed worldwide.
A towed passive acoustic monitoring (PAM) system comprises a streamlined array of two or more hydrophones, a tow cable, an electronics processing unit and a computer running specialised passive acoustic monitoring software. Towed PAM systems may be used on vessel based marine surveys that require real-time or archival monitoring of biological and anthropogenic sounds to facilitate the detection, classification and localisation of marine mammal species within the vicinity of the survey.
Analogue Towed Arrays
An analogue towed array detects changes in pressure waves and emits an electrical signal from the hydrophone sensors to the electronics processing unit where low and high frequency signal components are separated and digitised. Low and high frequency data are then processed and displayed in real-time using PAM software or monitored aurally with a headset. Analogue towed arrays are extensively deployed worldwide on vessels involved in geophysical surveys for the offshore energy and renewables sectors where marine mammal mitigation forms part of the survey license conscent.
4-ch 250-m Array Cable
The hydrophone array section consists of two broadband channels (0.2 kHz to 200 kHz, -3 dB points), two high frequency channels (2 kHz to 200 kHz, -3 dB points) and an array depth sensor. All four channels have a sensitivity of -195.6 dB re: 1 V/uPa and a +40 dB preamplifier gain. The hydrophones are grouped into pairs. Group 1 (H1 & H2) has a 2-m separation and group 2 (H3 & H4) has a 0.25-m separation. The distance between group 1 and group 2 pairs is 13-m. The array is integrated into a 250-m tow cable terminated with a ITT 19-way connector.
4-ch 20-m Array + 230 m Heavy Tow Cable
The hydrophone array section consists of two broadband channels (0.2 kHz to 200 kHz, -3 dB points), two high frequency channels (2 kHz to 200 kHz, -3 dB points) and an array depth sensor. All four channels have a sensitivity of -195.6 dB re: 1 V/uPa and a +40 dB preamplifier gain. The hydrophones are grouped into pairs. Group 1 (H1 & H2) has a 2-m separation and group 2 (H3 & H4) has a 0.25-m separation. The distance between group 1 and group 2 pairs is 13-m. The 20-m array is terminated with a Seiche Lemo connector and is compatible with a 230-m heavy-duty tow cable which is terminated with a Seiche Lemo connector at the array end and an ITT 19-way connector at the electronics end.
4-ch 20-m Array (LF) + 230 m Heavy Tow Cable
The hydrophone array section consists of two super broadband channels (10 Hz to 200 kHz, -3 dB points), two high frequency channels (2 kHz to 200 kHz, -3 dB points) and an array depth sensor. All four channels have a sensitivity of -195.6 dB re: 1 V/uPa and a +40 dB preamplifier gain. The hydrophones are grouped into pairs. Group 1 (H1 & H2) has a 2-m separation and group 2 (H3 & H4) has a 0.25-m separation. The distance between group 1 and group 2 pairs is 13-m. The 20-m array is terminated with a Seiche Lemo connector and is compatible with a 230-m heavy-duty tow cable which is terminated with a Seiche Lemo connector at the array end and an ITT 19-way connector at the electronics end.
4-ch 125-m Array (1-m spacing) + 230 m Heavy Tow Cable
The hydrophone array section consists of two super broadband channels (75 Hz to 200 kHz, -3 dB points), two high frequency channels (2 kHz to 200 kHz, -3 dB points) and an array depth sensor. All four channels have a sensitivity of -195.6 dB re: 1 V/uPa and a +40 dB preamplifier gain. The hydrophones are grouped into pairs. Both group 1 (H1 & H2) and group 2 (H3 & H4) have a 1-m separation. The separation distance between group 1 and group 2 pairs is 102-m. The 125-m array is terminated with a Seiche Lemo connector and is compatible with a 230-m heavy-duty tow cable which is terminated with a Seiche Lemo connector at the array end and an ITT 19-way connector at the electronics end.
4-ch 125-m Array (3-m spacing) + 230 m Heavy Tow Cable
The hydrophone array section consists of two super broadband channels (75 Hz to 200 kHz, -3 dB points), two high frequency channels (2 kHz to 200 kHz, -3 dB points) and an array depth sensor. All four channels have a sensitivity of -195.6 dB re: 1 V/uPa and a +40 dB preamplifier gain. The hydrophones are grouped into pairs. Both group 1 (H1 & H2) and group 2 (H3 & H4) have a 3-m separation. The separation distance between group 1 and group 2 pairs is 100-m. The 125-m array is terminated with a Seiche Lemo connector and is compatible with a 230-m heavy-duty tow cable which is terminated with a Seiche Lemo connector at the array end and an ITT 19-way connector at the electronics end.
6-ch 25-m Array + 230 m Heavy Tow Cable
The hydrophone array section consists of two low frequency channels (10 Hz to 24 kHz, -3 dB points), two broadband channels (0.2 kHz to 200 kHz, -3 dB points), and two high frequency channels (2 kHz to 200 kHz, -3 dB points) and an array depth sensor. All four channels have a sensitivity of -195.6 dB re: 1 V/uPa. The two low frequency channels have a +25 dB preamplifier gain, while the two broadband and two high frequency channels have a +40 dB preamplifier gain. The hydrophones are grouped into pairs. Group 1 (H1 & H2) have a 8-m separation, group 2 (H3 & H4) has a 2-m separation and group 3 (H5 & H6) has a 0.25-m separation. The 25-m 6H array is is terminated with a Seiche Lemo connector and is compatible with a 230-m heavy-duty tow cable which is terminated with a Seiche Lemo connector at the array end and an ITT 19-way connector at the electronics end.
3-ch Source-tow Array
The hydrophone array section consists of three broadband channels (0.2 kHz to 200 kHz, -3 dB points) with an output sensitivity of -195.6 dB re: 1 V/uPa and +40 dB preamplifier gain. H1 and H2 are groups as one pair and have a 0.25 m separation. H2 and H3 are group as a second pair and have a separation of 1.2 m. The array lemgth is 20 m in total and is terminated with 2 x AGM 1104M 4-way connectors in 1 m pigtail configuration for connection to a seismic airgun source array. The array is towed from a bridle shackled to the stern of the seismic source. Power and signal to the array is provided by a patch panel connection at the seismic contol unit. A short deck cable transmits the PAM signal from the patch panel output to the PAM system electronics, and from there to a local remote monitoring station (LMS) elsewhere on the vessel.
2-ch AutoNaut Array
2-Ch AutoNAut array is available in 10 m, 30 m or 100 m versions for compatibility with AutoNaut 5 m and AutoNaut 7 m and integration into Seiche MicroPAM system. H1 and H2 separation is 0.25 m with 1 m spacing from H2 to 2 bar depth sensor. Hydrophone specifications available to suit project needs but range from super broadband 10 Hz to 200 kHz or broadband 200 Hz to 200 kHz. Array comes with McCartney bulkhead Subconn (MCOM12M, FCR2012F) and Hirose Connector (JR25WR-16S(71)).
Digital Towed Arrays
The digital towed array houses up to 32 digital hydrophone sensors. Each hydrophone has an integrated minaturised low noise amplifier and 20 bit ADC which digitises the electrical signal prior to transmission along the array cable and therefore achieves a high singal to noise ratio. Each sensor is configurable in real-time for full control of gain and filters and target frequencies for detection. Additional modules within the array obtain environmental data on pressure, temperature and salinity and precise positioning information is acquired at key points through 3-axis compass and altitude sensors. Synchronised sampling provides increased versitility and beamforming capabilities. The electronics processing unit is contained within a robust housing that enables onward real-time data transmission over ethernet for display and processing.
Digital Thin Line Array
Seiche’s Digital Thin Line Array is a high-performance, low-noise acoustic array that provides highly sensitive passive acoustic monitoring. The array measures just 20mm in diameter and houses 8 digital hydrophone sensors, but can be configured for up to 32. The topside electronics are contained within a compact, robust housing.