EdgeTech, the leader in high resolution sonar imaging systems and underwater technology, recently delivered a new sonar system for the high-speed MMT Surveyor Interceptor ROV (SROV). The EdgeTech system is a dual frequency side scan sonar operating at 600/1600 kHz combined with a sub-bottom profiler operating at 1-10 kHz. The uniqueness comes in the custom Multi-pulse (MP) and Dynamically Focused (DF) capabilities of the side scan sonar. To ensure customers can take full advantage of the high-speed capabilities of the MMT Surveyor Interceptor ROV, the sonar needed to be able to produce high quality images while also operating at higher speeds than typically seen with work class or inspection class ROVs. The EdgeTech MP and DF technology perfectly fits the application.
Conventional side scan sonar systems are limited in transmit-receive cycle times by the sound propagation velocity of 1500m/s. Following the transmit pulse the sonar system has to wait for reception of the echo data from the farthest range before the cycle can repeat. This restriction results in ping rates that are adversely affected by range, and can severely limit the speed of the side scan sonar. With the ability place more than one sonar ping in the water simultaneously EdgeTech side scan sonars break this sound speed barrier. EdgeTech’s Multi-ping side scan sonar can transmit pulses during normal reception, without any cross pulse interference. This technique allows sonar ping repetition rates greater than those achieved with standard sonar.
Dynamically focused technology is a way to achieve higher resolution imagery at longer ranges when compared to conventional side scan sonar systems. Dynamic focusing is achieved through a virtual curvature and focusing of the arrays using software algorithms in association with a multi-segmented array consisting of a number of short linear elements. The effective result is higher resolution at longer ranges.
EdgeTech’s MP and DF technology on-board the high-speed MMT Surveyor Interceptor ROV was delivered in a compact 2205 AUV/ROV-based sonar package. The technology is also available in towed configurations.