Choosing the Right Sonar Imaging System for Autonomous Underwater Vehicles

Solstice mounted on the Saab Double Eagle.

Multi Aperture Sonar - a Low-logistics Alternative to SAS

Underwater vehicle operators have to make a choice when deciding on a sonar imaging system to integrate on their systems. The decision could result in a trade-off, with a choice to be made between achieving high levels of range and resolution, and power and weight budgets. The decision made can impact the value of subsea survey, classifying and mapping operations. But does it always have to be a trade-off? 

What is a multiple aperture sonar?

In multi-aperture sonar (MAS), the dynamically focused multibeam input from 32 elements is used to extend the focus along the whole swath. Multiple apertures further enhance the data and improve the signal-to-noise ratio. MAS sees further and at a higher resolution than traditional side-scan sonar. However, compared to synthetic aperture sonar (SAS), it has a shorter range and offers less resolution, which poses the question, when should we use MAS?

SAS the sensor of choice for large AUVs

Most commercial autonomous underwater vehicles (AUVs) are being used to survey the seafloor. This is due to the ability of AUVs to provide a stable sensor platform as well as being able to move along a predetermined set of waypoints. AUVs outperform all other platforms; they can survey for prolonged periods of time, at a set distance from the seafloor and sample at near constant speed. Since the value of the AUV is determined by its ability to survey, their value increases with improved sensing technol....

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