# ENDURUNS: An Integrated and Flexible Approach for Seabed Survey Through Autonomous Mobile Vehicles
## 1 Introduction
\begin{table}
\begin{tabular}{p{142.3 pt} p{142.3 pt}} \hline \hline
**Sensor Type** & **Use \& Description** & **Reference** \\ \hline \multirow{8}{*}{**Navigation sensors**: This calls of instruments is used as positioning sensors for underwater operations & **Acoustic baseline sensors**: they measure the phase of the incoming signal to determine direction. The result is a position derived from range and phase angle. & [31] \\  & **Doppler Velocity Log** (DVL): They measure the Doppler shift in the incoming signal reflected off the seabed (bottom track mode) or particles in the water (water track mode) column using the same principles as ADCP. Having several transducers pointing in different directions, velocity of all three axis is observable. & [32] \\  & **Pressure sensors**: Together with the estimate of gravity, these class of sensors are used to estimate the accurate depth or the speed of a vehicle. & [33] \\  & **Inertial sensors**: Integrating the acceleration and rate of changes of the orientation angles in the time domain provide state estimates for position, orientation angles velocities and accelerations. Inertial navigation systems use auxiliary sensors such as DVL, pressure sensors, acoustics or even GPS to augment the measurements. & [34] \\ \hline \hline \end{tabular}
\end{table} 
Table 1: _Cont._ \begin{table}
\begin{tabular}{p{142.3 pt} p{142.3 pt}} \hline \hline
**Application** & **Description** & **References** \\ \hline \multirow{8}{*}{**Research**} & **Seabed Morphology**: High-resolution bathymmetric and magnetic field maps of the seafloor for discovering and monitoring: scarps, active deformation and seismicity, submarine canyons and channels, fine-scale relief. & [22] \\  & **Water quality**: Mapping and monitoring of deep-water hydrothermal processes and water conditions. & [35] \\  & **Marine Life**: MBES, photographic and SSS surveys for coral reef, megabenthos and demerseral fish monitoring. & [36] \\  & **Biology Sampling**: Bed rock, boulder, coarse (mixed sediment), mega-ripples and fine rippled (sands and muddy sands) & [37] \\ \hline \multirow{8}{*}{**Industry**} & **Oil and Gas**: Pipelines and conductions monitoring, Underwater works as welding or maintenance management. & [38] \\  & **Electrical Lines**: Monitorization and repairs of cable lines in subsea environment & [29] \\  & **Military**: Inspections and surveys developed for army targets. Mapping of undiscover areas of interest for political or strategical motivation. & [39] \\ \hline \multirow{8}{*}{**Leisure**} & **Sports Events**: Using navigation methods for sea sports or marine challenges & [40] \\  & **Wrecks Inspections**: Using sonar and positioning technologies for ships or planes falling down detection and wrecks recovery operations. & [41] \\ \cline{1-1}  & **Films**: Cinema tool, specific cameras used to record marine environments for documental or films & [42] \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Applications where Autonomous Underwater Vehicles (AUV) are commonly used. system combined with a rechargeable battery pack, for both AUV and USV. Moreover, a long operative autonomy is ensured by an adaptive energy management [46]. Since the requirement and design phases of the project have been completed, this paper describes the ENDURUNS concepts design and the main AUV/USV system functionalities resulting from the first 18 months of research activities. A discussion of the main ENDURUNS achievements and future activities is provided. Finally, conclusions close the work and summarizes the main findings presented in this paper.