News

PRASYS Seminar - Tuesday 22 January 2019 - 1:30 PM

Amphi 3, Ensta Bretagne, 2 rue François Verny Brest

Published 1/18/2019

'A lesson from Mother Nature: biologically inspired processing techniques in automatic target recognition', Professor Hugh GRIFFITHS, 2017 IEEE Picard Medal, University College London

Abstract: Automatic Target Recognition is an important set of techniques in modern imaging radar and sonar. Useful insight can be provided from understanding how these processes have been optimised in anmials through the process of evolution. The talk will describe how bats have developed sophisticated echolocation signals and processing, and also how animals may deploy camouflage and deception techniques.

'Applications in shallow water remote sensing', Dr. Alan HUNTER, University of Bath

Abstract: Autonomous vehicles and underwater acoustic imaging systems have become valuable remote-sensing tools for the offshore and defence industries. While these tools have typically been deployed in relatively deep water (i.e., much greater than 10 m), they also have potential value for civilian and scientific applications in shallow and inland waters. However, these environments pose some challenges due to the confined underwater space and complex acoustic reflections. This talk will outline two different remote-sensing applications in very shallow water: 1. underwater crime scene investigation; and 2. breaking wave imaging in the surf zone.

' Imaging Internal Wave Structures', Professor Anthony LYONS, University of New Hampshire
Abstract: Linear structures, sometimes hundreds of meters in length, have recently been observed in seafloor imagery and bathymetry collected with both synthetic aperture sonar (SAS) and multibeam echosounder systems (MBES). This phenomenon is not due to the true morphology of the seafloor, but is caused by water column features related to the breaking of internal waves on a seafloor slope. Changes observed in acoustic intensity and bathymetry estimates are caused by the focusing of sound through structures with lower sound speed. In terms of seafloor mapping, these topography-mimicking features will impact the interpretation of imagery, may complicate the production of mosaics, and have the potential to cause bathymetric uncertainties exceeding International Hydrographic Organization standards. In terms of object detection, shadow zones may obscure targets of interest. In this talk it will be shown that these features may not be uncommon using examples of data collected with several different SAS and MBES systems in a variety of locations.

Display the whole heading