Estimation of 3D position, angle of attitude and orientation of free swimming fish in a hydro acoustic beam field under extreme lightning conditions / Bestemmelse af 3D position og orientering af frit svømmende fisk under extreme belysningsforhold

In order to be able to evaluate hydro acoustic signals from fish it is important to know the relation between these signals and the position and orientation of each fish. An experiment was set up in Hirtshals with two synchronized underwater cameras to follow one single fish while recording the hydro acoustic signal at the same time. Extraction of 3D position and orientation of the fish was possible in most cases, even though the lightning conditions were very complicated. A combination of sunshine and waves on the water surface created situations where the image processing failed. The project was collaboration between Danish Institute for Fisheries Research (DIFRES), North Sea Centre, Hirtshals and Aalborg University. (Henning Nielsen; Bo Lundgren, J. Rasmus Nielsen, Peter Faber, DIFRES)