Hydrophones, acoustic release transponders and a command and control unit for the transponders

Please note that this is a prior infromation notice and this notice is not a call for tenders. The information provided in this notice is preliminary and may change as the preparation progresses. The Natural Resources Institute Finland (Luke) is planning to purchase hydrophones, acoustic release transponders and a command and control unit for the transponders. Hydrophones are needed for research conducted on aquatic mammals to record their underwater calls and the surrounding underwater soundscape. The specific requirements for the hydrophones are: • Low power consumption, very low self-noise and 60 kHz bandwidth • Long battery endurance lasting up to 160 days • Must be able to provide up to 2 TB of removable data storage • Recording bandwidth of 20 Hz – 60 kHz • Sample rate of up to 192 kS/sec • Must provide a durable titanium housing • Must contain a removable protective hydrophone cage • Must be able to operate in depths of several hundred meter - up to 500 m depth rating • Must be suitable for up to 1 year deployments In addition, the hydrophones cannot be retrieved from depths by diving; thus, a remote release mechanism that brings the hydrophone up to the water surface is needed to accompany the hydrophone. The requirements for the release transponders are: • Must be compatible with the hydrophone type used in the project • >13 months deployment with alkaline battery pack • Integrated inclinometer • Uses a storage mode eliminating power consumption when not in use • Reliable, 'screw-off' release • Rugged, compact design • Working Load Limit of 150 kg • Depth rated to 1,000 m Further, a topside command and control unit is required to control and operate the release transponders. It should have the following requirements: • Must be robust and portable • Must communicate with release transponder RT 6-1000 from the surface • Must be able to operate in harsh marine environments. • High brightness, resistive touch screen display is required • Must come with an easy-to-use user interface • Must have a Lithium-Ion rechargeable battery that provides up to 8 hours of continuous operation • Must provide a secure acoustic communication link between the surface and seabed • Must have operational range of up to 1,000 m water depth • Must have operating temperature -20°C to +55°C • Must be able to export a complete set of activity logs for all activities and be able to export a PDF for release transponders

Companies that are interested in offering products that comply with the requirements set out above, are invited to send their contact details (name and e-mail address) by e-mail to hankintatuki@luke.fi with the subject "Hydrophones, acoustic release transponders and a command and control unit for the transponders". Please send the contact details by 18th of August 2026 at the latest.