Thermocline Tracking Using a Portable Autonomous Underwater Vehicle Based on Adaptive Threshold

Thermocline has a significant impact on marine fishery, navy submarine activity, ocean circulation and internal wave. In consideration of long range, low cost, and high maneuverability, the AUV (Autonomous Underwater Vehicle) is an ideal platform for ocean local precisely thermocline tracking. Combining with the advantage of the AUV yo-yo movement, this paper presents a simple and effective thermocline tracking method. According to the definition of the thermocline, we set a threshold, and in the real detect area, the threshold can change adaptively, thus we can draw the outline of the thermocline. Meanwhile, we present a method to determine bin size in order to solve the abruptness of robust and method's resolution. The simulation analysis was carried out using previous data of field test in the South China Sea.