Towed sub-bottom profiler Pesk-Avel

Pesk-Avel (Breton for “surface fish”) is a towed sub-bottom profiler for undertaking acquisitions on the continental shelf (depth range 20–200 m).

This system is integrated into a towfish which can be deployed from coastal vessels.

All the sub-bottom profilers are compatible and supported by the SUBOP data acquisition system.

Pesk-Avel  is used mainly for the following tasks:

- Studying sedimentation in estuaries and coastal areas, and the evolution of sedimentary systems.

- Acoustic profiling of sedimentary environments.

- Mapping sediments.

- Studying benthic ecosystems and characterizing habitats. 

Pesk-Avel operates near the surface, at a depth of less than 1 m in calm conditions and at about 2.5 m below the surface in rough waters, and at a speed of 5–6 knots. Depending on the wake generated by the boat, it operates at a distance of between 30 m (Thalia) and 70 m (L’Europe) from the stern.

The towfish is fitted with a mini attitude control unit and a pressure sensor. It is deployed using an electric winch and a 100 m electromechanical cable.

  • Water depth: 20–200 m
  • Penetration: approx. 50 m in loose sediment
  • Vertical resolution: 25 cm
  • Emission level: 193 dB ref. 1 µPa at 1 m
  • Electronics: Ixblue PWM 2 kVA
  • Signal: Chirp 1700–6000 Hz, 10–50 ms
  • Acquisition speed: 6 knots
  • Maximum swell height: 1.2 m
  • Towfish maximum dimensions (LxWxH): 1200 x 428 x 586 mm
  • Total weight in air (with devices fitted): 76 kg
  • Towfish weight in water: 27 kg
  • Winch maximum dimensions (LxWxH): 600 x 580 x 1085 mm
  • Weight of the winch (with cable): 188 kg
  • Winch electrical supply: 380 V
  • Winch electrical power: 250 W