A new, compact and cost-efficient concept for underwater range-gated imaging system
This will fill the current gap between short-range, high-resolution conventional video and long-range low-resolution sonar systems. UTOFIA offers a new modus operandi for the main targeted domains of application: marine life monitoring, harbor and ocean litter detection, fisheries and aquaculture stock assessment, and seabed mapping.
Range-gating reduces the effect of backscattering. In this figure an underwater object at a distance of approx. 9m is imaged. The graph shows the reflected signal from a laser pulse as a function of time. The first peak of the curve corresponds to backscattering from particles in the water. The second, attenuated peak corresponds to the reflection from the object that we are interested in (e.g., a lobster). The camera shutter is kept closed for approximately 50ns before it opens. Since the image is created from an integration of all light received, when the first 50 ns is gated out, most of the backscattering contribution to the fundamental noise is removed.
More information about the project can be found at the project website.