FAA Issues GPS Warning

[KG4CGC]

http://www.engadget.com/2011/01/20/faa-warns-of-ongoing-gps-issues-in-southeastern-us-due-to-defens/
You gonna get lost. lulz
Have a back up plan huh? Map?

That's according to a flight advisory just issued by the FAA, which warns pilots that their GPS signal "may be unreliable or unavailable" due to "GPS tests" that the Department of Defense will be conducting between January 20th and February 22nd.

[N7RJD]

Have a back up plan huh? Map?

I have a two stage backup plan. Stage one, have map. Stage two, don't let wife read map.
Hell, I can't drive upside down anyway.

[VE7DCW]

I'm betting there's a back-up plan with people on the runways guiding the way with laser pointers..... :agree:

[n2ize]

There is nothing strange about this. DoD needs the system for that time. So for that time period you backup everything with other navigational systems. Thhe Dod needs the system. And when the Dod wants something they GET IT!!

[KC2UGV]

There is nothing strange about this. DoD needs the system for that time. So for that time period you backup everything with other navigational systems. Thhe Dod needs the system. And when the Dod wants something they GET IT!!

Of course they get it if they need it. The DoD owns the system :)

[W3MIV]

People have been flying on instruments without GPS for a very long time. Airways and VORs work very well. Though I am told they are not replacing NDB units as they go down, the old ADF system is still available over much of the country. Doan need no steeenking GPS.

[KC2UGV]

People have been flying on instruments without GPS for a very long time. Airways and VORs work very well. Though I am told they are not replacing NDB units as they go down, the old ADF system is still available over much of the country. Doan need no steeenking GPS.

Yeah, 3 VOR's and you are just as accurate as GPS. 2, and your damned close. 1 + Dead Reckoning puts you rather close.

I know the alert said it could be inaccurate, but I'm wondering how? You can't take part of the system down, so I'm at a loss as to what is going on, since it needs to be damned accurate while used in military operations (Which are ongoing)...

[KA5PIU]

Hello.

GPS is actually 2 complete systems.
The low accuracy side is intended for a quick fix and the military side is encrypted.
But the FAA has a solution that works better than even the military side.
http://www.faa.gov/about/office_org/headquarters_offices/ato/service_units/techops/navservices/gnss/
Couple that with ADF and an FM-BCB ADF and one can get a fix of as little as 2 inches, and that is how some survey equipment works.
Want an even closer fix? set up a base with your rover.
http://www.topconpositioning.com/products/gps/
Even without GPS you can get a fix of around 200 feet with ease.
AM radio stations can provide that level of accuracy.
But, nearly all of the good GPS receivers now have WAAS.
http://en.wikipedia.org/wiki/Wide_Area_Augmentation_System
http://www8.garmin.com/aboutGPS/waas.html
Add to that the Russian system.
http://en.wikipedia.org/wiki/GLONASS
And there is no reason for an outage.
A laptop can easily be equipped with a Glonass receiver as well as a GPS/WAAS unit and use both.

[Chris]

dod can fooch the gps readings for non dod gps users while keeping their users accurate in times of conflict, but Russia has made a gps service and China likely has one too so if the dod fooches their gps the only folks who will be fooched is, once again, the US citizen

[KC2UGV]

Hello.

GPS is actually 2 complete systems.
The low accuracy side is intended for a quick fix and the military side is encrypted.
But the FAA has a solution that works better than even the military side.
http://www.faa.gov/about/office_org/headquarters_offices/ato/service_units/techops/navservices/gnss/
Couple that with ADF and an FM-BCB ADF and one can get a fix of as little as 2 inches, and that is how some survey equipment works.
Want an even closer fix? set up a base with your rover.
http://www.topconpositioning.com/products/gps/
Even without GPS you can get a fix of around 200 feet with ease.
AM radio stations can provide that level of accuracy.
But, nearly all of the good GPS receivers now have WAAS.
http://en.wikipedia.org/wiki/Wide_Area_Augmentation_System
http://www8.garmin.com/aboutGPS/waas.html
Add to that the Russian system.
http://en.wikipedia.org/wiki/GLONASS
And there is no reason for an outage.
A laptop can easily be equipped with a Glonass receiver as well as a GPS/WAAS unit and use both.

GPS is ONE system Rudy. A fudge factor is sent on every signal, which is then removed by military GPS units with the proper keys loaded by a K1C unit.


dod can fooch the gps readings for non dod gps users while keeping their users accurate in times of conflict, but Russia has made a gps service and China likely has one too so if the dod fooches their gps the only folks who will be fooched is, once again, the US citizen

They do it daily, every day. So, I'd hazard your idea is correct, they are playing with the fudge factor to see how much of one they can insert before their own devices suffer.

[KA5PIU]

Hello.

Actually there are 2 systems in place.
The first is the L1/L2 system.
There is no longer a "Fudge factor" as selective availability has been turned off in 2000 under the Clinton administration.
http://en.wikipedia.org/wiki/Global_Positioning_System
In 2005 a new series of satellites was launched that provides an independent system for military use, the M-Code.
http://en.wikipedia.org/wiki/GPS_modernization
The M-Code uses both geostationary satellites as well as the LEO birds.
This was done due to the fact that the Russians got GLONASS running again with help and funding from China.
Not to be outdone, the EU is getting its act together with its own system, not operational.
http://en.wikipedia.org/wiki/Galileo_(satellite_navigation)
China has an operational system in place at this time.
http://en.wikipedia.org/wiki/Beidou_navigation_system
The Chinese and Russian systems are independent of each other but receivers for the Chinese system can use both as one system.
The ability to use 2 systems as one is the primary reason the Chinese system works at this time.

[W3MIV]

Yeah, 3 VOR's and you are just as accurate as GPS. 2, and your damned close. 1 + Dead Reckoning puts you rather close.

Never flown with 3 VOR heads; never even seen an a/c with three. Plenty of hardware with 2, some plus the GPS. Never flew with a GPS, though. My experience was limited to VOR, and it was one or none; and the only one I was used to was a blue/yellow type. ;)

[KA5PIU]

Never flown with 3 VOR heads; never even seen an a/c with three. Plenty of hardware with 2, some plus the GPS. Never flew with a GPS, though. My experience was limited to VOR, and it was one or none; and the only one I was used to was a blue/yellow type. ;)

Hello.

The newer glass cockpits allow for up to 5 VOR fixes at the same time.
This is done with one receiver that can scan and a plotting function.
Since the scanning is done quickly there is no lag whatsoever.
And of course this is a VORTAC, so you get the DME as well.

[Chris]

arent beacons what billy jeff clinton used to guide ron browns airplane into that mountain?

[KA5PIU]

Hello.

Beacons are another thing altogether.
http://en.wikipedia.org/wiki/Non-directional_beacon

[ab1ga]

I don't think they're touching the satellite signals at all. Changing the signal of a given satellite would change the pseudoranges obtained from that satellite from the entire coverage area, which is much, much larger than the area shown on the map.

If I were a betting man, I say that something very interesting is going on at the center of that circle on the map. If it's radiating in the L band where GPS lives, then it could interfere with the receivers in the area. Could be an attempt to determine GPS susceptibility to spoofing, investigations into new jamming methods for our use against other powers, or electromagnetic compatibility testing of an unrelated system.

Need to buy some tin foil now...

[KE7DKN]

Hello.

The newer glass cockpits allow for up to 5 VOR fixes at the same time.
This is done with one receiver that can scan and a plotting function.
Since the scanning is done quickly there is no lag whatsoever.
And of course this is a VORTAC, so you get the DME as well.

A VORTAC is a facility on the ground, not something in the aircraft.

[KA5PIU]

A VORTAC is a facility on the ground, not something in the aircraft.

Hello.

Everything about this was referring to what is in an IFR rated aircraft.
http://www.avweb.com/news/avionics/183230-1.html
One can say VOR-DME just as one can say Aviation Electronics.
But most people simply say Vortac and Avionics.
People now say dish or satellite to refer to a receiver and antenna, just as they say cable to refer to the TV service.
And, yes, they really do say satellite and point to the dish outside. ;)

[KE7DKN]

Hello.

Everything about this was referring to what is in an IFR rated aircraft.

I don't think a DME is required for IFR aircraft certification, but whatever.


http://www.avweb.com/news/avionics/183230-1.html
One can say VOR-DME just as one can say Aviation Electronics.
But most people simply say Vortac and Avionics.

No, one shouldn't, and no, they don't. VOR-DME and VORTAC are not even the same thing. They're even listed separately in your link.

The TACAN (the "TAC" in VORTAC) is for military aircraft. For civil aviation, the difference between VOR-DME and VORTAC is transparent since both types of installations supply the same info, but they are not interchangeable.

Airmen talk about VORTAC when they're talking about that specific kind of installation - most likely when referring to it on a map. The instrument in the aircraft is referred to as "the VOR." The DME is usually mentioned separately ("the VOR and DME"), which is fitting since they are separate pieces of equipment.


People now say dish or satellite to refer to a receiver and antenna, just as they say cable to refer to the TV service.
And, yes, they really do say satellite and point to the dish outside. ;)
Sounds like those are people who don't know any better.

Pilots (real ones :squint:) tend to be a bit more knowledgeable about these things and will use accurate language when discussing aviation.