The Shallow Underwater Vision Profiler or UVP (CNRS patent) is designed to study large (>100 µm) particles and zooplankton simultaneously and to quantify them in a known volume of water. The UVP system makes use of computerised optical technology with custom lighting to acquire digital images of zooplankton IN SITU down to depths of 600m.
The UVP acquires only in-focus images in a volume of water delimited by a light beam issued from red light-emitting diodes (LEDs) in 100µs flashes. The typical light beam illuminates an area of 4x20 centimetres which gives a sampling volume of 1 litre per image. When interfaced with conventional CTD measuring devices, the distribution of particles and fauna can be displayed in real time integrated with the CTD metadata. The high-resolution digital image can then be processed by the computer.
The UVP's software monitors the system status and handles communications with both user and camera. Acquisition and process sequences can be controlled by the ship-board observer or from a support vehicle such as an ROV or an AUV. Moored systems allow long deployments where thousands of time-programmed sequences of images to be acquired. The software also monitors data from up to 8 analogue sensors which are synchronized with images.