anyone running GPS clocks in Southeastern Georgia?

Gary E. Miller gem at rellim.com
Fri Jan 21 12:27:04 CST 2011


-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Yo All!

On Fri, 21 Jan 2011, Matthew Kaufman wrote:

> I'm not sure how you'd get increasing radius with altitude from anything but a
> jammer near sea level.

Agreed.

One of these tests was recently run in Utah and we saw the effects
in Central Oregon well outside the NOTAMed area.  During the tests,
airplanes using GPS navigation would suddenly lose RAIM and had to
abort their approach to landing.  Not sure if they lost all GPS nav
information or just RAIM.

For non pilots, RAIM is an indicator that the GPS has a redundant
solution that matches the barometrically measured altitude.  GPS will
continue to report a nav solution when lacking this redundancy but
pilots are not allowed to shoot an approach when RAIM is off.

Good thing most air carriers do not use GPS yet.

No effects seen on the ground here, but we were several hundred miles
from the test.

RGDS
GARY
- ---------------------------------------------------------------------------
Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97701
	gem at rellim.com  Tel:+1(541)382-8588

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.3 (GNU/Linux)

iD8DBQFNOc/9BmnRqz71OvMRAltbAKDW62I7B4Heg1KLAbZaYiShhro5vQCgu5fM
WUWTwQhT5tTajslbe3GtuXY=
=Czhk
-----END PGP SIGNATURE-----





More information about the NANOG mailing list