Lindsay Gee

Interactive 3-D visualization: a tool for seafloor navigation, exploration and engineering

Recent years have seen remarkable advances in sonar technology, positioning capabilities, and computer processing power that have revolutionized the way we image the seafloor. The massive amounts of data produced by these systems present many challenges but also offer tremendous opportunities in terms of visualization and analysis. The authors have developed a suite of interactive 3D visualization and exploration tools specifically designed to facilitate the interpretation and analysis of very large (10s to 100s of megabytes), complex, multi-component spatial data sets. If properly georeferenced and treated, these complex data sets can be presented in a natural and intuitive manner that allows the integration of multiple components each at their inherent level of resolution and without compromising the quantitative nature of the data. Artificial sun-illumination, shading, and 3D rendering can be used with digital bathymetric data (DTMs) to form natural looking and easily interpretable, yet quantitative, landscapes. Color can be used to represent depth or other parameters (like backscatter or sediment properties) which can be draped over the DTM, or high resolution imagery can be texture mapped on bathymetric data. When combined with interactive analytical tools, this environment has facilitated the use of multibeam sonar and other data sets in a range of geologic, environmental, fisheries, and engineering applications.

Dealing with increasing data volumes and decreasing resources

The US Naval Oceanographic Office (NAVOCEANO) has recently updated its survey vessels and launches to include the latest generation of high-resolution multibeam and digital side-scan sonar systems, along with state-of-the-art ancillary sensors. This has resulted in NAVOCEANO possessing a tremendous ocean observing and mapping capability. However, these systems produce massive amounts of data that must be validated prior to inclusion in various bathymetry, hydrography, and imagery products. It is estimated that the amount of data to be processed will increase by an overwhelming 2000 times above present data quantities. NAVOCEANO is meeting this challenge on a number of fronts that include a series of hardware and software improvements. The key to meeting the challenge of the massive data volumes was to change the approach that required every data point to be viewed and validated. This was achieved with the replacement of the traditional line-by-line editing approach with an automated cleaning module, and an area-based editor (ABE) integrated with existing commercial off-the-shelf processing and visualization packages. NAVOCEANO has entered into two cooperative research and development agreements (CRADAs) - one with the Science Applications International Corporation (SAIC), Newport, RI, USA, and the other with Interactive Visualization Systems (IVS), Fredericton, N.B., Canada, to integrate the ABE with SAICs SABER product and IVSs Fledermaus 3D visualization product. This paper presents an overview of the new approach and data results and metrics of the effort required to process data, including editing, quality control, and product generation for multibeam data utilizing targets from digital imagery data and automated techniques.