Wavefront has published an insightful article detailing the advantages of Multi Aperture Sonar (MAS) compared to Synthetic Aperture sonar (SAS).
In discussions about our sonar technologies, certain questions frequently arise among potential clients. Specifically, when it comes to our Solstice product, which utilizes Multi Aperture Sonar (MAS), many inquire about the reasons for choosing MAS over Synthetic Aperture Sonar (SAS) and the appropriate contexts for each.
To provide clarity, we consulted Dr. Rob Crook, our Director of Research, for his expert insights on this topic. Here’s his perspective:
When is Multi Aperture Sonar the better choice over Synthetic Aperture Sonar?
Solstice represents Wavefront’s innovative Multi Aperture Sonar (MAS) solution. While it operates similarly to high-performance traditional side-scan sonar, its processing methodology is distinct. Solstice leverages multibeam data from 32 elements to dynamically enhance focus across the entire swath. This multi-aperture approach not only refines the data but also boosts the signal-to-noise ratio. Furthermore, Solstice’s array is engineered to mitigate multi-path effects, enhancing the visibility of shadows and highlights crucial for object detection and classification. It generates narrow 0.15° along-track beams and boasts an remarkable 200m swath.Designed for mounting on Autonomous Underwater Vehicles (AUVs), Solstice operates with minimal power consumption.
utilizing an AUV equipped with Solstice allows for greater visibility and higher resolution compared to traditional side-scan systems. However, when comparing MAS to SAS, it is significant to note that MAS typically has a shorter operational range and lower resolution.
What are the reasons for transitioning from SAS to MAS?
In the design of AUVs, certain trade-offs are certain, especially concerning Size, Weight, and Power (SWaP) constraints. For vessels primarily focused on surveying, where power usage is less of a concern, SAS can be advantageous. It can operate continuously while consuming hundreds of watts, which is manageable within their power budgets.
Conversely, for low-logistics systems, the situation is quite different. Popular two-person portable systems face stringent SWaP limitations. Even SAS systems can require two to three times the power of Solstice.
Moreover, SAS systems tend to be bulky and heavy, making them impractical for compact setups. Fitting a SAS on a 9-inch diameter platform is nearly unfeasible. The size of SAS systems means that even on larger AUVs, operators must compromise on mission endurance due to reduced SWaP availability for other instruments.
This is where Solstice’s MAS technology shines. Consuming only 21 watts (including data acquisition), it matches the leading AUV side-scan sonars in terms of power efficiency. Yet,it delivers a range and precision that is unparalleled among side-scan sonars. in terms of accuracy, Solstice performs exceptionally well over the initial 50-metre swath, rivaling top SAS systems. At a 75-meter range, its accuracy exceeds that of the nearest side-scan sonar by more than double. Additionally, unlike competitors, Solstice can gather data over a 200m swath with a 100m range on either side. With its motion compensation and interferometry capabilities, Solstice is compact and lightweight, making it ideal for two-person portable applications.
MAS is perfectly suited for speedy, low-logistics, long-endurance, high-resolution missions on auvs, particularly those operated by smaller crews. In essence, this makes it an excellent choice for 95% of AUVs operating in coastal regions!
