Computer scientists at the Naval
Research
Laboratory's Virtual Reality (VR) Lab are exploring
ways to
provide information to individual warfighters without
distracting them from the operating environment (i.e., keeping
the warfighters' hands free and their view on the real-world)
as well as to enhance the flow of information between tactical
command centers and personnel in the field. Focusing on operations
in urban areas, where there are many unique and challenging
conditions,
the researchers have developed a wearable 3-D
system that gives
users in the field real-time information
about their environment.
The system, called the Battlefield
Augmented
Reality System (BARS), provides users with a "heads-up"
display. The user wears a see-through head-mounted display through
which the user sees the real world. Computer generated graphics
and text are overlaid atop the real world in the display. From
the user's point of view, these graphics seem to be aligned directly
with objects in the environment. For example, a user might see
a computer-generated "signpost" which appears to be
attached to the side of a building. As the user turns their head,
the label will remain fixed to the side of the building.
Why concentrate on urban
environments?
"Because city terrain is complex and
presents serious challenges
to command-and-control
systems," says Dr. Lawrence Rosenblum,
director of the NRL
VR Lab. Buildings above street level, especially
high-rise
buildings, can conceal threats such as snipers. Below
street
level, networks of sewers and tunnels may hold other risks.
Cityscapes also make it difficult to plan and coordinate group
activities. It is nearly impossible for all members of a team
to be in direct line of sight of one another when navigating
narrow or crowded streets.
Furthermore, notes the VR
Lab's Dr. Simon Julier, the urban environment
is highly dynamic
and constantly changing. Dangers, such as the
positions of
snipers, can change continuously. And, the structure
of the
environment itself can evolve. For example, damaged buildings
can fill a street with rubble, making a once-safe route impassable
and once-familiar terrain unrecognizable.
Why use augmented reality? Unlike
other
approaches (such as those which use handheld electronic
maps),
users wearing an augmented reality system does not have
to take
their attention away from the environment itself where
threats
might suddenly appear. Furthermore, augmented reality
automatically places the graphics directly on top of the real-world
environment.
BARS
consists of two main components:
the Wearable Augmented Reality
System (WARS) and the 3-D Interactive
Command Environment
(3DICE). WARS is the unit worn by the user
in the field. It is
a self-contained backpack system, which includes
the wearable
computer, tracking system, see-through head-mounted
display,
interaction devices and a transceiver for wireless communication.
The WARS users receive reports and orders from the 3DICE, and
can enter simple situational reports simply by speaking, gesturing,
or using a personal digital assistant.
Strategic planners in the 3DICE
might be
hundreds or thousands of miles from the area of action.
Using
information received from the WARS users and other sensor
systems, the command constructs a tactical picture of the
environment.
On the basis of this tactical picture and input
from other decision
support tools, commands are sent to users
in the field.
Constructing the BARS system
poses both software
and hardware challenges to the researchers.
Despite the
availability of powerful laptops and personal digital
assistants, there is no computer currently available that meets
the physical size requirement and has the capability of rendering
3D stereo images. Furthermore, say the researchers, because many
of today's systems are self-contained consumer products, they
cannot be extended through the addition of extra hardware. Several
mobile computers under development are still unnecessarily large
and heavy, but current advancements in GPS, sensor and computing
technologies will solve these problems shortly.
The BARS system is being developed
in collaboration with Columbia University. NRL research is focusing
on algorithms and system integration, including such issues as
tracking and calibration, information filtering, display, usability,
and augmented reality (AR) system architectures. NRL is considering
what information should be displayed (e.g., which buildings should
have their labels displayed) and on precise registration (the
alignment of the graphics with the real world). Researchers at
Columbia are focusing on AR architecture issues and on methods
to control how information will be displayed . For example, if
there are labels that name five different buildings, how do should
those labels be placed so that they are in a convenient location
on the display and do not overlap one another?
Augmented reality, says Julier,
has the potential to fundamentally revolutionize the way in which
data is delivered to warfighters, disaster management teams,
hostage rescue teams and any other group in which complicated,
spatial data must be presented to a user in an environment.
Furthermore,
it offers great potential as an aid to training
individuals through
allowing a user to interact with a virtual
simulation while in
a real environment. However, there are many
research issues that
are yet to be overcome. These range from
hardware (such as the
development of compact and robust
tracking systems) to user interface
design issues (what
information will be shown to the user and
how?). As a related
issue, the researchers need to consider how
the users will have
to be trained to effectively use the new
forms of
information.
To date, BARS focus is a research and
development system that
is fully operational within NRL. It is
expected that BARS, which
is funded by the Office of Naval
Research, will be ready for
field-testing the system by 2004.
The U.S. Naval Research Laboratory is the Navy's full-spectrum corporate laboratory, conducting a broadly based multidisciplinary program of scientific research and advanced technological development. The Laboratory, with a total complement of nearly 2,500 personnel, is located in southwest Washington, D.C., with other major sites at the Stennis Space Center, Miss., and Monterey, Calif. NRL has served the Navy and the nation for over 85 years and continues to meet the complex technological challenges of today's world. For more information, visit the NRL homepage or join the conversation on Twitter, Facebook, and YouTube.
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