Ship-mounted USBL system with phase interferometry bearing estimation and range-dependent accuracy
Ultra-Short Baseline (USBL) systems mount a compact transceiver array on a surface ship or buoy. Unlike LBL which requires deployed seafloor transponders, USBL provides mobile positioning capability. The system measures range via acoustic time-of-flight and bearing via phase interferometry across a small baseline (10-20cm). Accuracy is typically 1% of slant range.