Geospatial Case Study
AVS Technology Turns Mountains of Data Into Maps of Ocean Floor
Since Australia is an island nation with nearly 80 percent of its trade transported by sea, it is vital to supply the world’s fleets with accurate paper and electronic navigation charts. These charts help ensure maritime travel to be safer, and shipping movement to be more direct, efficient and less costly. Further, with accurate charts, shipping is less likely to disturb the fragile environment and ecosystems of Australia’s coast, particularly important since the Great Barrier Reef stretches 1,250 miles along the east coast.
The Royal Australian Navy Hydrographic Service is responsible for gathering data and producing the charts that contain all of the information required for safe navigation: depth values, contour values, navigation marks and topographic features.
With more than 12,000 miles of coastline to map, the process involves a massive amount of data being converted into civil and military paper and electronic nautical charts. The Hydrographic Office employs the latest in laser technology to gather depth information, and the latest in computer technology to analyze it. The Navy uses powerful software and information systems from the small, technically savvy company Hydrographic Sciences Australia, Pty, Ltd. (HAS) to help automate the chart production process. Founded in 1992, HAS, in turn, has relied upon AVS/Express to build the graphic display subsystem.
Gathering the hydrographical data
The Laser Airborne Depth Sounder (LADS) incorporated by the Australian Navy has simplified the process of sounding the ocean floor. LADS is a scanning system mounted on a survey aircraft that can acquire 350,000 soundings per hour. This process is much faster than the traditional “pinging” of shipboard acoustical technology used to discover the nature of the ocean floor. LADS data, combined with data from other sources, form the base data for a nautical chart. The data may contain millions of soundings, each comprising several attributes that indicate accuracy and level of confidence of the sounding.
Automated chart production
Presented with this magnitude of data, the Royal Australian Navy Hydrographic Service was unable to manually assess massive data sets and reduce the high number of soundings to a lower, more manageable figure that chart making requires. Instead, the Navy turned to HAS 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 HAS.
“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.”
The solution developed for the Navy is a hydrographic processing package that converts the soundings from different sensors and stores then in a spatial database. The system allows the user to retrieve the data for any defined area and assess it for quality before it is used to compile the chart. Many indicators such as coverage, sounding density, and tide correction are best checked visually. That is why HAS selected the most powerful visualization tool on the market as SeaScape’s post-processor.
AVS/Express contains functionality for data visualization, image processing, data display and database access. Working as a subsystem of SeaScape, these features of AVS/Express are put to use accessing the spatial database and displaying 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.
HSA conducted its own survey of third-party graphics display systems before selecting AVS/Express. “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.”
HSA is among the leading developers of hydrographic information technology and digital navigation systems in the world, and includes among its clients the hydrographics offices of the United Kingdom, New Zealand, and Scandinavia, as well as other government, defense and commercial maritime organizations.
AVS/Express was proposed and sold to HAS and continues to be serviced by Visualiation Systems, the local Advanced Visual Systems’