GPS Sole Source Civil Aviation Navigation?

On 9/28/2006 3:59 PM, SirRichardCraniumEsq. wrote the following:
Has any thought been given to the disparity in altitude between spy
camera satellites and the GPS constellation?

SNIP


Working with the speed of light(LASER)it probably does not matter that
much.


Beam dispersion, hence diminishing energy density at the target, and pointing
accuracy are two considerations that come immediately to mind. In addition to
the simple geometry of pointing accurately at something farther away, every
thousand miles of orbit height adds something more than ten milliseconds of
delay to your aiming feedback control loop. And since you are talking about
ground based weapons you probably have the atmosphere causing your beam to wave
around in a significant way. It may be that only space based weapons of this
type are even feasible. I don't know. Maybe someone who does will pipe up.

If the Chinese can hit a spy satellite I am sure they can figure out a
way to zap a GPS bird. If not right now soon in the future.


There is a big difference between illuminating a bird with the minimal amount of
energy density required to temporarily blind its camera and delivering enough
energy to kill the bird. Note that now they are not even killing the cameras
though they might be able to do that. Remember that it isn't enough to just
(accurately) get energy to a target -- it must be absorbed and not reflected
away. This issue is not exactly a new one for military satellite designers.

America should establish a good solid VOR/DME back up network on the
ground hardened for EMP attacks with back up power and redundancy.


Electromagnetic pulses big enough to cause wide scale ground damage of
electronics come only from nuclear detonations, which tend to cause other
difficulties that could make VOR availability a fairly minor priority. There
are those pesky gamma rays hitting all that live meat, for example. Also the
(unhardened) ground and spaced-based assets of the domestic telecommunications
network.

The FAA as always is walking backwards with their future planning and
right now are looking at decommissioning ground based navaid's soon.

That is just stupid


Possibly, but illogical and unscientific arguments don't prove it.