Agencies buy into 3-D
- By Natasha Haubold
- Apr 10, 2000
Accurately tracking a hurricane can mean the difference between life and
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.