Using 3D is 2nd Nature to Scientists
If scientists can't get to Mars in person, seeing it through
three-dimensional (3-D) imagery is the next best thing. Thanks to
FIDO's cameras, called "stereo pairs," which enable the
creation of three-dimensional images, the science team is able to learn
more about the terrain and geologic processes that formed the area than
they could with only two-dimensional (2-D) images.
"If your work is limited to 2-D images," explains Nathalie
Cabrol, "the problem is that you don't get an understanding of the
volume or shape of objects or terrain." Nathalie is a geologist from
SETI Institute located at NASA Ames Research Center who uses 3-D
imagery almost daily. Through 3-D imagery, geologists can observe the
geometry of an object, which will tell something about the processes that
formed and affected that object. For instance, if the object from the 3-D
image looks rounded or smooth, it could have been weathered over time
by water. If it is irregular and scoured, perhaps a glacier or volcano
"During the FIDO test today we're looking at outcrops,"
says Nathalie. "Looking at them in the 3-D image tells me where
there is an actual protrusion and where my brain is playing tricks on a
2-D image. Yesterday, I was researching the tops of some valley walls that
looked like tight catwalks. It was really hard to see their thickness from a
2-D image. When I put the 3-D glasses on, I could see enormous
protrusions and discovered that the catwalks were actually sturdy and
robust layers that must have been formed over many years."
Three-dimensional imagery is also very important when planning a
traverse because it allows you to understand the slope or gradation the
rover might encounter. If a slope is too steep or the ground is too loose,
it might be too dangerous for the rover to climb it. Although you can see
slopes in 2-D images, a 3-D image allows for greater accuracy and an
even better understanding of the materials that make up the slope.
Nathalie has had many experiences that have convinced her of the
necessity of acquiring images in 3-D. If she's not using 3-D imagery, she's
out in the real word. She does research in the field of planetary aqueous
environments and their analogs (equivalents) on Earth. For example,
Bolivia is home to the highest lake on Earth, which is 20,000 feet
(6,000 meters) above sea level. This area resembles ancient lakebeds on
Mars because it is a volcanic environment that is usually covered by ice
and heated by thermal hot springs. Like Mars, it has a thinner atmosphere
and experiences high radiation and low oxygen levels.
"Using the glasses are second-nature to us, and we can really
get a feel for what it's like on Mars." Three-dimensional images
are "a good substitute for being in the field," says Nathalie,
"but if I had my choice, I'd be in the field myself."