VLA – Vertical Line Array

The Vertical Line Array (VLA) is a system for recording, visualizing and storing underwater acoustic signals.

The VLA can continuously record four acoustic signals, covering all frequencies from 30Hz to 100kHz. The system is capable of sampling rates up to 384 kS/s on all four channels simultaneously. Acoustic signals are sampled with a resolution of 16 bits and stored as WAVE files. Time and GPS position are also stored in an accompanying .csv file.

The system consists of the following parts:

Vertical line consisting of a 225m cable with connectors for four hydrophones, each placed 30m apart, and mechanical termination at both ends.

Adjustable bottom loaded to straighten the line vertically.

Four hydrophones with protective cages, to be attached to the vertical line.

Winch to release and pull the line.

The control station, which contains all the electronics needed for data acquisition, including battery backup.

GPS receiver for time synchronization and position logging.

Robust computer for control, visualization and storage of the recorded acoustics.

Deck cable to connect the center socket of the winch drum to the control station.

The control station includes an audio output jack (3.5 mm) and a 4-channel audio mixer that allows the operator to listen to the acoustics in real time. The PC software visualizes frequency spectrum (FFT) plots and amplitude plots for a selected channel in real time, as well as logging status, position and time information. The PC software also includes controls to start/stop recording, and options to configure sample rate and wave file and log file settings.

Scanmatic can adapt VLA to the customer’s needs.

The four VLA hydrophones with protective cage in a robust Pelicase.