Side-scan sonar based SLAM for the deep sea

In order to robustly perform SLAM (Simultaneous Localization and Mapping), places need to be recognized when they are visited again. In the deep-sea environment SLAM-assisted navigation based on side-scan sonar data benefits from using three-dimensional features of the environment as they are much less view-dependent than classic 2D features. Obtaining these features requires processing of the sonar data as the side-scan sonar sensor readings contain three dimensional information only indirectly. To extract that information the ensonification process needs to be inverted. This inversion is an ill-posed inverse problem and therefore regularization is needed before a unique solution can be found. Once the true seabed shape is reconstructed, wide area SLAM techniques can be applied.