Case Study: Mapping Australia's Coast for Maritime Travel

Nearly 80 percent of Australia's trade is transported by sea. To reduce the danger of maritime travel, improve shipping efficiency, and protect the fragile environment and ecosystems of Australia’s coast, the Royal Australian Navy Hydrographic Service gathers data to produce highly accurate navigation charts including depth values, contour values, navigation marks and topographic features.

More than 12,000 miles of coastline must be represented in paper and electronic nautical charts, so the Hydrographic Office employs the latest laser technology to gather depth information and the latest computer technology to analyze it. In particular, powerful software and information systems from the small, technically savvy company Hydrographic Sciences Australia, Pty Ltd. (HSA) helps automate the chart-production process. HSA, in turn, relies on AVS/Express to build the graphic display subsystem.

The Navy simplifies the sounding process with the Laser Airborne Depth Sounder (LADS), a scanning system mounted on a survey aircraft that can acquire 350,000 soundings per hour. LADS data, combined with data from other sources, forms the base data for a nautical chart and encompasses millions of soundings, each comprising several attributes that indicate accuracy and level of confidence of the sounding.

Rather than manually assess massive data sets and reduce the high number of soundings to a lower, more manageable figure, the Navy turned to HSA for software and information systems that could help automate the chart-production process.

"In developing our SeaScape system to facilitate the Navy’s sounding selection and bathymetric contouring process, we knew we would need a very fast display subsystem that could manipulate three-dimensional sea floor models consisting of thousands of data points," said Brian O’Neil, managing director of HSA. "We selected AVS/Express because we wanted SeaScape to supply high quality graphics in a simple-to-use format. Further, we didn’t have the resources, nor could we spare the time, to develop our own portable, powerful, full-function graphics renderer. The functionality we were able to include in SeaScape was possible only with a tool like AVS/Express."

Using AVS/Express, HAS developed a hydrographic processing package that converts the soundings from different sensors and stores them in a spatial database, then allows the user to retrieve the data for any defined area and assess its quality before using it to compile the chart. Because indicators such as coverage, sounding density, and tide correction are best checked visually, HSA selected the most powerful visualization tool on the market to serve as SeaScape’s post-processor.

AVS/Express's data visualization, image processing, data display and database access functions work as a subsystem of SeaScape to access the spatial database and display sea floor models as triangulated irregular networks, using different color tables based on attributes assigned by the coloring key. Additionally, SeaScape can display other types of data such as mainland and island features that have been gathered from the Navy’s GIS.

"We chose AVS/Express because it has the flexibility to handle the irregular data structures we experience in hydrographic applications, without imposing any limits on the amount of data to be displayed. And SeaScape deals with huge volumes of data," said O’Neil. "Further, it is such an intuitive and easy-to-use tool, that it increases our developers’ productivity. And because it can be applied across several platforms, we are not constrained by particular hardware and operating systems."