Info Express Delivers Sonar Imaging System

Marine Electronics

September 1988 Sea Technology Magazine

The sonar imaging and data acquisition system delivered last month to the Royal Australian Navy (RAN) sets a new standard for user-friendly sidescan sonar search and survey operations. For experienced geophysicists or the naval reservist in training, learning the dual-frequency Info Express system is easier than most video arcade games.

To accomplish the task of simultaneously processing and storing two sidescan images, a new system configuration was designed and implemented. Rather than processing each frequency on a separate system, Info Express designed a single system, controlled from one interactive workstation, capable of correlating both sonar images. The system integrates the towfish position data (received via an RS-232 interface to the navigation system) with the image data in real time. Using the trackball to control the image screen cursor, the true positions of sonar contacts are digitized and added to the target database as the search progresses.

At lower range settings, when ping repetition rates are as high as 14 per second, the system continuously generates over 5 GBytes of data each minute and stores it directly to high capacity optical disc cartridges. In order to keep up with the higher data acquisition rates and still incorporate the real time features that impressed the Australians (such as image enhancement, image zoom, and target annotation) the system software was rewritten from the core level to optimize each routine and module. At the same time a user interface was added utilizing pull-down windows and pop-up help screens, which makes learning and operating the system easy, a requirement for the reservists who have been assigned the mine surveillance task.