Short-Range Ultra-Low-Cost Anti-Submarine Sensors

Insuring the safety and control of littoral waters is problematic because of the difficulties of surveillance. The preferred methods of surveillance in the ocean are acoustic. In littoral waters, acoustic methods fail because noise from the surf and reflections from the shallow bottom convolute acoustic signatures beyond our capacity to discern them. Water absorbs light, reducing the effectiveness of surveillance using visual methods. We propose that a sensor based on entrainment is the most effective means of protecting a perimeter in littoral waters.