Reacquisition and imaging of mine-like targets in very shallow water using the CetusII AUV and MIRIS high-resolution sonar

The Lockheed Martin Perry Technologies CetusII is an autonomous underwater vehicle with unique capabilities for underwater object relocation and imaging. Defined by requirements derived from the need operate from small available deployment assets and be employed in shallow water/very shallow water environments, the CetusII was developed as a highly maneuverable hover-capable 2-man portable system capable of being rapidly deployed with minimum support needs. The CetusII vehicle has been equipped with a unique new forward looking sonar tailored for AUV relocation and inspection of underwater objects. The Mine Reacquisition and Imaging Sonar (MIRIS) employs high-frequencies and physical lens-based beamforming to provide near-photographic image quality in a compact low-power implementation. Employing coordinate information of potential targets which have been provided by area reconnaissance vehicles, CetusII dynamically develops and revise plans which optimize it´s capability to revisit and reacquire the targets. This requires that the behavior and functions that control the actions of CH incorporate the operational characteristics of the MIMS sensor in terms of range and field of view as well as well as information regarding the a priori positional accuracy of the potential targets and the vehicle´s navigational accuracy. The CetusII digitally collects and stores MIRIS image data during the reacquisition of the target for post mission evaluation and identification of mines. This paper describes the integration of the CetusII vehicle with the MIMS sonar and the enhancements to the Multisensor Integrated Robotic Architecture (MIRA) which were made to provide the required capabilities. The on-vehicle image collection methodology and feature evaluation is described in the context of in-water testing and demonstration of the operational system