SE United States GPS Issues Until 22 Feb

[canderson]

For those of you living in the southeastern part of the U.S., be advised that your signal quality and lock ability may be degraded between now and 22 February 2011.

The DoD will be performing some "tests" (jamming?) between now and then. While the FAA Flight Advisory addresses outages of 45 out of every 60 minutes at altitude, centered around a set of coordinates in the ocean (they translate to N30?14.100 / W80?28.183), and specify that the radius of the "disruption" will decrease at lower altitudes, your TomTom may have more trouble achieving lock in areas of normally decreased signal -- especially in NE Florida, E Georgia, and S South Carolina.

https://www.faasafety.gov/files/notices/2011/Jan/GPS_Flight_Advisory_CSFTL11-01_Rel.pdf

 

[gatorguy]

IF they're truly running tests (note the outages center in the Bermuda Triangle) then maybe I'll get an opportunity to check out the jamming test function on my nuvi's. It's one of those odd diagnostics they include.

 

[canderson]

Just beginning to get suspicious reports of positioning errors down that way this morning. Users standing side by side with two quality Garmin handhelds in Durham, NC reported sudden shifts of 90' or so. That can be enough to place a "road snapped" unit like a TomTom on an adjacent frontage road or exit.

This is going to make for some unhappy geocachers for a while, I'm afraid. 90' in that hobby might as well be a mile much of the time.

 

[canderson]

Looks like the problem is going to be far more widespread than initial anticipated. The following list of NOTAMs (Notice to Airmen) covers a whole lot more geography than the original notification did. Not sure why.

as of: Sat, 22 Jan 2011 01:37:00 UTC

ZAB ALBUQUERQUE (ARTCC),NM.


!GPS 01/014 ZAB NAV GPS IS UNRELIABLE AND MAY BE UNAVAILABLE WITHIN A CIRCLE WITH A RADIUS OF 345 NM AND CENTERED AT N355652/W1173458 OR LOCATION ALSO KNOWN AS 88 DEGREES AND 70 NM FROM THE TTE VOR AT FL400; DECREASING IN AREA WITH A DECREASE IN ALTITUDE TO A CIRCLE WITH A RADIUS OF 305 NM AT FL250; A CIRCLE WITH A RADIUS OF 230 NM AT 10,000FT MSL AND A CIRCLE WITH A RADIUS OF 185 NM AT 4,000FT AGL 1500-1530 AND 1630-1900 DLY WEF 1101191500-1101231900



ZDC WASHINGTON (ARTCC),DC.


!GPS 01/004 ZDC NAV GPS IS UNRELIABLE AND MAY BE UNAVAILABLE WITHIN A CIRCLE RADIUS OF 370 NM AND CENTERED AT 304906N/0802811W OR LOCATION ALSO KNOWN AS 105.25 DEGREE RADIAL 52.1 NM FROM THE SSI VOR AT FL400; DECREASING IN AREA WITH A DECREASE IN ALTITUDE TO A CIRCLE WITH A RADIUS OF 325 NM AT FL250; A CIRCLE WITH A RADIUS OF 260 NM AT 10,000 FEET MSL AND A CIRCLE WITH A RADIUS OF 215 NM AT 4000 FT AGL 0000-0245 DLY WEF 1101200000-1102110245


ZDV DENVER (ARTCC),CO.


!GPS 01/015 ZDV NAV GPS IS UNRELIABLE AND MAY BE UNAVAILABLE WITHIN A CIRCLE WITH A RADIUS OF 345 NM AND CENTERED AT N355652/W1173458 OR LOCATION ALSO KNOWN AS 88 DEGREES AND 70 NM FROM THE TTE VOR AT FL400; DECREASING IN AREA WITH A DECREASE IN ALTITUDE TO A CIRCLE WITH A RADIUS OF 305 NM AT FL250; A CIRCLE WITH A RADIUS OF 230 NM AT 10,000FT MSL AND A CIRCLE WITH A RADIUS OF 185 NM AT 4,000FT AGL 1500-1530 AND 1630-1900 DLY WEF 1101191500-1101231900


ZJX JACKSONVILLE (ARTCC),FL.


!GPS 01/007 (KZJX A0032/11) ZJX NAV GPS IS UNRELIABLE AND MAY BE UNAVAILABLE WITHIN A CIRCLE RADIUS OF 370 NM AND CENTERED AT 304906N/0802811W OR LOCATION ALSO KNOWN AS 105.25 DEGREE RADIAL 52.1 NM FROM THE SSI VOR AT FL400; DECREASING IN AREA WITH A DECREASE IN ALTITUDE TO A CIRCLE WITH A RADIUS OF 325 NM AT FL250; A CIRCLE WITH A RADIUS OF 260 NM AT 10,000 FEET MSL AND A CIRCLE WITH A RADIUS OF 215 NM AT 4000 FT AGL 0000-0245 DLY WEF 1101200000-1102110245


ZLA LOS ANGELES (ARTCC)PALMDALE, CA.


!GPS 01/016 (KZLA A0139/11) ZLA NAV GPS IS UNRELIABLE AND MAY BE UNAVAILABLE WITHIN A CIRCLE WITH A RADIUS OF 345 NM AND CENTERED AT N355652/W1173458 OR LOCATION ALSO KNOWN AS 88 DEGREES AND 70 NM FROM THE TTE VOR AT FL400; DECREASING IN AREA WITH A DECREASE IN ALTITUDE TO A CIRCLE WITH A RADIUS OF 305 NM AT FL250; A CIRCLE WITH A RADIUS OF 230 NM AT 10,000FT MSL AND A CIRCLE WITH A RADIUS OF 185 NM AT 4,000FT AGL 1500-1530 AND 1630-1900 DLY WEF 1101191500-1101231900


ZLC SALT LAKE CITY (ARTCC),UT.


!GPS 01/017 ZLC NAV GPS IS UNRELIABLE AND MAY BE UNAVAILABLE WITHIN A CIRCLE WITH A RADIUS OF 345 NM AND CENTERED AT N355652/W1173458 OR LOCATION ALSO KNOWN AS 88 DEGREES AND 70 NM FROM THE TTE VOR AT FL400; DECREASING IN AREA WITH A DECREASE IN ALTITUDE TO A CIRCLE WITH A RADIUS OF 305 NM AT FL250; A CIRCLE WITH A RADIUS OF 230 NM AT 10,000FT MSL AND A CIRCLE WITH A RADIUS OF 185 NM AT 4,000FT AGL 1500-1530 AND 1630-1900 DLY WEF 1101191500-1101231900


ZMA MIAMI (ARTCC), FL.


!GPS 01/006 (KZMA A0028/11) ZMA NAV GPS IS UNRELIABLE AND MAY BE UNAVAILABLE WITHIN A CIRCLE RADIUS OF 370 NM AND CENTERED AT 304906N/0802811W OR LOCATION ALSO KNOWN AS 105.25 DEGREE RADIAL 52.1 NM FROM THE SSI VOR AT FL400; DECREASING IN AREA WITH A DECREASE IN ALTITUDE TO A CIRCLE WITH A RADIUS OF 325 NM AT FL250; A CIRCLE WITH A RADIUS OF 260 NM AT 10,000 FEET MSL AND A CIRCLE WITH A RADIUS OF 215 NM AT 4000 FT AGL 0000-0245 DLY WEF 1101200000-1102110245


ZNY NEW YORK (ARTCC) RONKONKOMA NY.


!GPS 01/008 (KZNY A0028/11) ZNY NAV GPS IS UNRELIABLE AND MAY BE UNAVAILABLE WITHIN A CIRCLE RADIUS OF 370 NM AND CENTERED AT 304906N/0802811W OR LOCATION ALSO KNOWN AS 105.25 DEGREE RADIAL 52.1 NM FROM THE SSI VOR AT FL400; DECREASING IN AREA WITH A DECREASE IN ALTITUDE TO A CIRCLE WITH A RADIUS OF 325 NM AT FL250; A CIRCLE WITH A RADIUS OF 260 NM AT 10,000 FEET MSL AND A CIRCLE WITH A RADIUS OF 215 NM AT 4000 FT AGL 0000-0245 DLY WEF 1101200000-1102110245


ZOA OAKLAND (ARTCC) FREMONT,CA.


!GPS 01/018 (KZOA A0018/11) ZOA NAV GPS IS UNRELIABLE AND MAY BE UNAVAILABLE WITHIN A CIRCLE WITH A RADIUS OF 345 NM AND CENTERED AT N355652/W1173458 OR LOCATION ALSO KNOWN AS 88 DEGREES AND 70 NM FROM THE TTE VOR AT FL400; DECREASING IN AREA WITH A DECREASE IN ALTITUDE TO A CIRCLE WITH A RADIUS OF 305 NM AT FL250; A CIRCLE WITH A RADIUS OF 230 NM AT 10,000FT MSL AND A CIRCLE WITH A RADIUS OF 185 NM AT 4,000FT AGL 1500-1530 AND 1630-1900 DLY WEF 1101191500-1101231900


ZTL ATLANTA (ARTCC),HAMPTON,GA.


!GPS 01/005 ZTL NAV GPS IS UNRELIABLE AND MAY BE UNAVAILABLE WITHIN A CIRCLE RADIUS OF 370 NM AND CENTERED AT 304906N/0802811W OR LOCATION ALSO KNOWN AS 105.25 DEGREE RADIAL 52.1 NM FROM THE SSI VOR AT FL400; DECREASING IN AREA WITH A DECREASE IN ALTITUDE TO A CIRCLE WITH A RADIUS OF 325 NM AT FL250; A CIRCLE WITH A RADIUS OF 260 NM AT 10,000 FEET MSL AND A CIRCLE WITH A RADIUS OF 215 NM AT 4000 FT AGL 0000-0245 DLY WEF 1101200000-1102110245

 

[canderson]

Got word from the Tampa area that GPS reception went sideways at around 7pm this evening.

 

[daveoftruro]

Does anyone know whether this problem is limited to the USA or are other parts of the world affected as well?

 

[canderson]

As far as I know, the tests are only related to the airspace (primarily) and below (to a lesser degree) over the U.S. Haven't seen any NOTAM information related to outages or weirdness elsewhere. What you see above are the areas they thought to be impacted by the tests.

What I'm hearing so far is that they're deliberately throwing up some interference to assure that their own system will operate in spite of it.