Functions of the HERMES application

The HERMES application is the configuring interface for the echo sounders EK60/EK80/ME70 on the ships of the French Oceanographic Fleet. It enables the user to secure the acquisition of data using standard pre-established configurations for different types of cruise or series of cruises.

Water column sampling is optimized automatically according to depth in order to avoid multiple echoes from the sea floor.

During acquisition an interface enables the user to monitor the proper acquisition of data and to predict the acoustic performance of the configuration used.

Functions of the MOVIES3D application

The MOVIES3D application features modular architecture. The various modules for processing the raw data from the echo sounders were developed in C++ and optimized for processing in real time during the acquisition of the data.

These modules can be used to replay the HAC files in the MOVIES3D application. They can also be leveraged using Matlab or Python for exploratory processing on large data sets.

The main modules of MOVIES3D are:

  • Compensating for calibrations of echo sounder intensity, the attitude of the platform, and absorption losses depending on the parameters of the environment.
  • Processing raw signals for building echograms and spectrograms in the case of pulse-frequency modulation (PFM).
  • Extracting regular layers, schools by spatial contiguity and single echoes according to criteria of amplitude and phase.
  • Displaying the frequency and angular responses of targets.
  • Supervised echo-integrating in order to classify detections into echotypes for the purpose of estimating quantities per species.
  • Visualizing raw and segmented echoes in a 3D environment.