Doppler water-track aided inertial navigation for autonomous underwater vehicle

Navigation of underwater vehicles has been and remains a substantial challenge to all underwater platforms.With the emergence of new applications and the growing acceptance of autonomous underwater vehicles (AUVs) in both military and civilian institutions, comes the need for enhanced accuracy and robustness, sustainability, and de-risking. This paper reports the development and experimental evaluation of a state-of-the-art inertial navigation system (INS) for underwater vehicles. The proposed system improves underwater navigation capabilities both for vehicles lacking conventional velocity measurements, and for systems where the need for autonomy, robustness and integrity is important, e.g. during sensor dropouts or failures, or in case of emergency navigation. Together with real-time sea current estimation, Doppler velocity log (DVL) water-track measurements are integrated in the navigation system to provide velocity aiding for the INS. Complementary aiding sources include ultra short base line (USBL) acoustic positioning and DVL with bottom-track. The performance is evaluated on data from a field-deployed AUV, demonstrating the effectiveness, robustness, and sustainability of the proposed navigation system.