Agencies buy into 3-D

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, Md.

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.