FGS Signal Generators can hold up to eight signals. A single Signal Generator is used where the target fish species are migratory and or non-resident, whilst an eight Signal Generator is generally required for resident species to avoid habituation to any one signal.
The Signal Generator feeds into a bank of audio frequency power Amplifiers that boost signal levels to the required output levels for the transducers.
A temperature/pressure resistant pipe delivers air from the air blower or compressor to the BAFF control equipment.
The Diagnostics Units monitor the output of the Amplifiers and condition of the Sound Projectors and send an alarm to a monitoring site if a fault is detected.
The Signal Generator, Power Amplifiers and Diagnostics and Alarm Units combine to provide the Control Equipment of a SPA system. The Control Equipment is typically housed in an air-conditioned enclosure, or an enclosure within an air-conditioned building.
Underwater Sound Projectors are used to create the underwater sound field. Generally, a linear array of Sound Projectors is used to create a field of repulsion. We refer to this array as the ‘Sound Projector Array’ or SPA. The Model 15-100 Sound Projector is primarily intended for shallow freshwater applications (<5m), while the Model 30-600 is used in deeper coastal applications, and for larger installations where a greater sound field is required.
Generally underwater grade cables connect each Amplifier to a series of Sound Projectors. All of the connections use underwater mateable connectors.
A deployment system allows the Sound Projectors to be raised and lowered for inspections and maintenance and also avoids the costs associated with using divers. Deployment systems may take many forms ranging from a simple rail to a custom made structure.
The majority of systems now supplied by FGS are SILAS systems, incorporating High Intensity Lights with the acoustic signal. SILAS systems are based upon Sound Projector Arrays, but the components have been updated, and the main components are outlined in the SILAS System Description.