Comments,
questions, suggestions?
Send us your feedback by emailing lab-notes@coe.berkeley.edu.
|
A
Force Field for No-Fly Zones
Speaking as a pilot, the idea is outlandish. To be at all
useful, such a system would necessarily be impossible for
a pilot to disable or bypass.
I challenge you to name any existing aircraft electronic
system of even one-tenth the complexity required for "soft
walls" that has not failed and needed to be disabled
for flight safety.
You're trying to solve a problem that has already solved
itself. No one will ever again successfully take over an
airliner. Before 9-11, the best move was for passengers
to cooperate. That will never again be the case.
—
Keith Burton - PP, ASEL; Wyncote, PA
Response from Edward Lee
Pilots frequently react this way to the Softwalls proposal.
A pilot comes from a 2000-year-old tradition of the "captain
of the ship," where even the authority to marry the
passengers is granted. The captain is responsible for the
ship, its crew, and its passengers, and the tradition dictates
absolute control over all elements of the craft. Presumably,
this is why transponders in commercial aircraft have an
"off" switch in the cockpit. The Sept. 11 hijackers
used this "feature" to delay detection of their
intentions. In retrospect, it is clearly unconscionable
to grant pilots this authority. The risk of a fatal malfunction
in the transponder is so small compared to the damage done
by turning it off that the safety of the people on the ground
trumps the pilot's authority.
The fact that equipment fails is real. The skepticism about
new devices in aircraft is healthy. But the fact is that
aircraft have consistently gotten both more complex and
safer. This particular pilot probably should never assume
control of Boeing 777, since the fly-by-wire electronics
removes all mechanical couplings so that if the cockpit
electronics fail, then the craft will crash.
This pilot claims that the problem has solved itself. Apparently,
the Pentagon does not agree, since critical sites in Washington
DC are now protected by antiaircraft batteries. In my opinion,
the mere presence of this protection scheme poses a far
greater risk to pilots, crew, and passengers than that posed
by the risk of failure of well-designed cockpit electronics
(witness the impressive safety record of the 777).
You asked for my opinion on "soft walls", giving me the choice
between "science fiction" and "homeland security". Given those
choices, I'd have to call it science fiction. I've even *seen*
it in science fiction (specifically _Stations of the Tide_,
by Michael Swanwick, 1991, ISBN 0-380-71524-4, in Chapter
12, entitled "Across the Ancient Causeway"). I'm sure it is
really fun to work on, and perhaps is a funding magnet in
these times of national security driven research, and I know
that those two things alone are sufficient. As the article
said, the computer security aspects of the system are a "huge
concern". Any database of no-fly-zones can be outdated, subverted,
or just plain pithed. And what about "griefers", as they are
called in the gaming world? Can a big jetliner be herded into
a no-fly-zone by a number of small aircraft, while trying
to avoid collision with them? Thanks for your time.
—
Dan Liddell
|
|
Sharing
A Vision
The success of a ShareCam would seem to rest in the idea that
a
democratically-activated camera is more interesting than fixed
view or a view that moves through a preprogrammed routine.
I think a related computer experiment would be to use a higher
resolution
camera (3 or 4 megapixel) that provides a fixed image of a
scene and then serve a 200x200 pixel feed of any portion of
the image, at any requested resolution, to any number of users.
The first user could request a one-to-one pixel resolution
of a specific object and see their request at 72dpi in either
real time or at whatever refresh rate is designated by the
software. Another user could request a one-to-four resolution
of the same area while another could request a view from a
different area of the image entirely. You could even view
the entire image at once in all its compressed glory.
Each user could then "move" their camera as they
see fit and feel as if they are in complete control of what
they see. The question is: how could you pull multiple data
requests from the same source image simultaneously and feed
the results to many different recipients? Especially if the
image is refreshing every second or faster.
— Matt Budke
Response from Dezhen Song, PhD Candidate
Thanks for your feedback for ShareCam system. The high resolution
camera available today can offer 3~5Mega pixeled image. The
problem is those high end cameras have same horizontal field
of view as low end versions. The stand HFOV with tolerable
quality is about 50~60 degrees, which is not able to cover
the 180 degree pan range if using only one camera. It is possible
to use multiple cameras but cost and complexity of the system
will increase a lot.
On the other hand, it is possible to use a panorama camera
to cover more than 180 degrees. But, as mentioned in Ken's
email, a significant distortion will be introduced by its
lens. Panorama cameras usually come in low res versions. So,
it is hard to correct the distortion by mathematic transformation
if the initial information is too limited.
|
Comments may be edited for clarity.
Lab Notes is published online by the Public Affairs Office of the UC Berkeley College of Engineering. The Lab Notes mission is to illuminate groundbreaking
research underway today at the College of Engineering that will dramatically change our lives tomorrow.
Editor, Director of Public Affairs: Teresa Moore
Writer, Researcher: David Pescovitz
Designer: Michele Foley
Subscribe or send comments to the Engineering Public Affairs Office: lab-notes@coe.berkeley.edu.
© 2003 UC Regents.
Updated 7/31/03.
|
