Sonar signals arriving at a target, or the towfish, from a single source but along different paths. In the sonar sciences, multipath echoes can be problematic. Multipath returns in imaging sonar typically occur in shallow water or around complex structures such as petroleum platforms or near piers and pilings. A classic multipath environment for side scan sonar is in shallow water with a flat sea surface.
Nadir gap – Refers to the acoustic “gap” located directly underneath an AUV platform, which is a product of the side-looking sonar system.