Re: GPS + Pulsars + an apology/rebuttal

On 23-Feb-02 at 11:29, Thomas Barclay (kaladorn@magma.ca) wrote:
> Question:
> Can we duplicate or fake a pulsar? If so, could 
> we mess up people's navigation? Could we 
> interfere with signals from a pulsar? Or cancel 
> them via some form of interference? 

Well, you could fake it if you want to go back into
the past 50 years or so and beam your fake to where
your opponents will be.  :)

> When establishing our own space beacons (SPS 
> - GPS in space), would we use some sort of 
> pulsar like signal, but with more uniqueness?

Who is going to put in beacons that will only be good
after the signal gets across some large number of
(light) years?

> You did not, in fairness, mention that the US can 
> also (you did build, and did pay for, and do 
> own - AFAIK - the constellation) turn off the 
> feeds from some satellites entirely or probably 
> even deactivate the whole shebang if it really 
> wants to black out an area. 

We would have to shut down commercial air traffic
to do this.  They are relying fairly heavily on
it.  For that matter they are placing GPS units
in large automated farm machines now.  What I
don't understand is how they are claiming accuracy
within inches when GPS is within a meter.  The
discussion on Science Friday on NPR claimed increased
yields by making the automatic weeding closer to
the plants.

Oh, and as for the bashing.  Either:

1.  It's true, and we should either fix it or shut up
    about it.

2.  It's false and not worth getting upset about.