Please do not mis-attribute others' remarks to me. I did not post the quoted
material.

"Ray Andraka" wrote in message
...
| Nope, GPS for aviation is essentially one frequency with code modulation.
The
| receiver picks out the different satellites by correlating the code
sequence
| against the received signal. The code sequences are orthagonal, which
means they
| are enough different that you only get a strong correlation peak for the
one
| satellite that matches the code you are correlating against. The long
code
| sequences provide a very high processing gain, so the signals can be
buried in a
| good deal of noise, however it is relatively easy to jam the entire system
with a
| strong transmittter on the carrier frequency. This is what RAIM is all
about. It
| doesn't even have to be an intentional jammer: intermodulation from TV
transmitters
| in close proximity has caused local outages, for example.
|
| It would be much harder to jam the entire VOR band because the VOR
signals are
| transmitted at much higher power (3 orders of magnitude), and the VOR band
covers a
| wide frequency band relative to the frequency of the center of the band.
|
| Scott Moore wrote:
|
| C J Campbell wrote:
|
| Bull****. GPS also works using multiple satellites and multiple
frequencies.
| If you are going to propose that the entire frequency band for GPS be
jammed
| or otherwise corrupted, then the same thing would work across the entire
| VOR band as well.
|
| --
| --Ray Andraka, P.E.
| President, the Andraka Consulting Group, Inc.
| 401/884-7930 Fax 401/884-7950
| email
| http://www.andraka.com
|
| "They that give up essential liberty to obtain a little
| temporary safety deserve neither liberty nor safety."
| -Benjamin Franklin, 1759
|
|