UACE2017 Proceedings: On the problem of resolution for fully coherent CSAS system

• Session:
  Towards Automatic Target Recognition. Detection, Classification and Modelling
• Paper:
  On the problem of resolution for fully coherent CSAS system
• Author(s):
  Yan Pailhas, Yvan Petillot, Bernard Mulgrew
• Abstract:
  ATR (Automatic Target Recognition) for MCM (MineCounter Measure) operations is highly dependent on resolution and image quality. The introduction of SAS (Synthetic Aperture Sonar) systems, more than a decade ago, has then been a game changer in the field of MCM. It became clear over the years however that single pass survey may not be sufficient to reach acceptable levels of recognition and/or false alarm. The interesting problem of target reacquisition has then emerged. For synthetic aperture systems, circular reacquisition patterns are particularly beneficial for various reasons: (1) it offers the full 360 degrees view angles of the target, (2) it maximises the aperture offering the maximum theoretical resolution for the system and (3) it is relatively efficient in term of reacquisition time. This presentation focuses on the resolution problem for CSAS systems. Thanks to the symmetry of the problem, we will derive the exact CSAS PSF (Point Spread Function) at the centre of the reacquisition pattern, then extend the exact PSF expression to the full field of view using atom wave wavelet analysis. We will naturally derive a new definition for resolution based on the PSF energy leakage. The PSF is not uniform for the full view area, and we will introduce two normalisation methods to remediate this issue. Finally, we will show how to increase further the CSAS resolution and then the image quality using pulse adapted wave atom deconvolution.
•   Download the full paper

Contact details

• Contact person:
  Dr Yan Pailhas
• e-mail:
  
• Affiliation:
  Heriot-Watt University
• Country:
  United Kingdom