Object detection with sector scanning sonar

The object detection subsystem is the foundation to object avoidance and path planning. It plays an active role in supporting the operations of an autonomous underwater vehicle (AUV). The first challenge with the implementation of an object detection subsystem for an AUV is in identification of a detection system. The considerations for implementing the sector scanning sonar over other acoustic and video imaging alternatives were based on the factors of its small size, lower power consumption, data rate and visibility. The next challenge is on achieving a reliable object detection subsystem. We review the Otsu thresholding and static thresholding for object detection using the sector scanning sonar. The proposed static thresholding is based on the methodology of an adaptive thresholding with constant false alarm rate (CFAR). Several modifications to the detection methodologies are proposed along with their advantages and disadvantages are also be presented. Experimental dataset collected at Republic of Singapore Yacht Club (RSYC) is used to evaluate the detection methodologies.