WASHINGTON (04/10/2000) - Accurately tracking a hurricane can mean the difference between life and death.
When Hurricane Floyd hit the North Carolina coast last year, the National Oceanic and Atmospheric Administration was able to give residents several hours' warning thanks to 3-D images created at the agency's Visualization Lab in Silver Spring, Maryland.
Last month, NOAA used the same technology to predict the path of several cyclones that devastated Mozambique. And in February, astronauts aboard the space shuttle Endeavour collected 3-D data of the Earth's terrain that will help guide weapons and make flight simulators more realistic.
Many agencies across government have discovered the benefits of 3-D technology, using it for diverse tasks such as predicting weather and volcanic eruptions and for designing improved ocean-going ships and spacecraft. Because it can be used to help save lives as well as money, additional future spending on 3-D technology is almost certain.
"3-D helps people better understand information," said Allan Eustis, director of NOAA's Visualization Lab. "Creating a digital [3-D] Earth will give us a better understanding of the world around us."
For example, during Hurricane Floyd, NOAA used superimposed satellite pictures to create a 3-D image that provided scientists with a 360-degree view of the storm. "It was like being inside a NOAA storm chaser plane inside the storm," said NOAA spokesman Greg Hernandez. The Navy has used this ability to visualize data in three dimensions to save millions of dollars in ship design fees, according to a Navy study.
Computer Aided Virtual Environments (CAVE) allow shipbuilders to simultaneously visualize, design and test the ship's layout. The CAVEs make it easier to find areas that may need redesign by providing a 360- degree, 3-D view of the operational and living areas, as well as the weapons controls, communications and navigation station layouts. Likewise, NASA has used 3-D technology to develop and design agency equipment and ships. In 1997, NASA teamed up with StereoGraphics Corp. to create several 3-D virtual prototypes of the Mars Pathfinder Mission's Sojourner rover. Spacecraft designers used StereoGraphics' CrystalEyes and Monitor Zscreen to simulate Mars terrain in 3-D.
But NASA hopes to take 3-D imaging one step further by using advanced thinking software to design systems -- such as those that could be developed for the international space station -- that are more tolerant of error.
The agency's goal is to develop intelligent tools that give people the sense of total immersion and provide geographically distributed design team members the sense of working simultaneously on the same piece of equipment. That will give NASA significantly more knowledge of a design before it commits to a program.
"Virtual reality is not enough," NASA Administrator Dan Goldin said during a March 15 House Appropriations Committee's Veterans Affairs, Housing and Urban Development and Independent Agencies Subcommittee meeting. "We want total immersion in three-dimensional space to simulate how to build the space station." What makes two-dimensional objects appear to the eye as three-dimensional is an effect called stereoscope. Stereoscope, similar to a View-Master toy, creates two images from the left and right eye perspectives.
The images are then brought together on a computer screen, and special glasses help the eyes adjust to the rapid screen fluctuations.
For 3-D mapping projects, that means that two sets of data or images must be collected, which is what the National Imaging and Mapping Agency did during Endeavour's recent nine-day Shuttle Radar Topography Mission.
The use of the dual radar devices -- one inside the shuttle, the other on a 200-foot carbon mast -- allowed for two images to be taken at the same time.
One device measured the strength of the reflected radar light and determined the texture of the surface. The second radar determined land elevations by recording the color of light reflected.
"You can't get 3-D images with only one radar unless you take two pictures of the same area," said Joe Steel, a topographer for NIMA. "In the past, that would have required two trips and relying on the camera being lined up in the same position. Now, we can take two images at once and not worry about any discrepancies in locations."
The 3-D images collected by NIMA will help the U.S. Geological Survey predict volcano eruptions and monitor land movement. The pictures also will make it possible for the weather service to better predict storm movements.
Paula Shaki Trimble contributed to this article.