Frowning takes 68 muscles.
Smiling takes 6.
Pulling this trigger takes 2.
I'm lazy.
Posted on 03/17/2010 6:04:52 PM PDT by Aussie Dasher
National security will be just fine. It's the folks with commercial GPS that will be impacted. The military uses an encrypted channel that runs at 10x the data rate of the C/A channel used by a common GPS. The encryption sequence is unique over a 2 week period and the keys are not available to the public.
Any pilot worth his salt can fall back to using VOR or TACAN for navigation. Many high end aircraft also have inertial navigation that is completely independent of other systems on the aircraft. This is nothing but a sensational "scare" story to sell some fish wrap.
Is US military GPS jam proof?
I don’t consider airports used by small jets commercial.
If you consider charter commercial so be it.
Put another way, no air carrier airport has had it’s IFR approach decommisioned and gone to GPS only.
Next Gen hasn’t even been funded and Congress is still fighting over it and just today they introduced a bill to fund the FAA for 90 days to give them extra time to fight over funding.
I remember reading about how Saddam had gps jammers in Iraq ...
I have jammed (it really was an accident) a GPS satellite - the signal we (accidental) emitted, the bird failed to receive it's time update from the source in CO.
Then again, not everyone has access to a multi-gigawatt (Erp)autotracking jammer. The point is, almost anything can be jammed with brute force jamming.
Ya, it was that high power - we would bounce a signal from the moon from time to time as part of a test routine. I miss my old job, to say the least.
Nothing that uses radio waves is jam-proof.
Some secure comms hop between frequencies, so that jamming is impractical -- it would require jamming way too much spectrum, would shut down way too much RF communication, and would be dead easy to track. I don't know if secure GPS uses something similar, but even that could be denied for a short period of time in a small area.
Dallas Love Field has ten instrument approaches. four are ILS, six are GPS. Dallas Ft. Worth has sixteen GPS approaches. Atlanta Hartsfield has twenty GPS approaches. Chicago O’Hare has fifteen GPS approaches. You were wrong.
You said “No air carrier airport has had it's IFR approach decommissioned and gone to GPS only.” Would you like make a little wager on that? How about the airports served by commuter airlines that have had a GPS overlay on their existing NDB or VOR approach, and then the NDB or VOR has been decommissioned?
You don't know the definition of air carrier. I have an air carrier certificate that looks exactly like the ones possessed by Delta, American, etc. The difference between those operations and mine is that they fly scheduled routes, I fly on demand. The training, standards and inspections that we both go through are nearly identical.
You said “If you consider charter commercial so be it.” Yes, I do consider charter commercial. So does the FAA, the insurance carriers, airport management, the IRS, and my many satisfied customers who enjoy flying ten thousand feet higher than the airlines, above the weather, in luxury, on their schedule, and without a TSA strip search.
Jamming a GPS signal will bring down an airplane??? Where do these idiot “reporters” get this stuff? Are they really that stupid?
[What does the TITLE say, bonehead?]
I quote from the OP- “AN electronic device small enough to fit in a shirt pocket and big enough to bring down an airplane can be easily bought over the internet for just $55. Fox News reports that all a terrorist needs is a credit card and $55 to buy a GPS jammer used by car thieves in the UK.
I chose to read the OP instead of the title. Titles are often misleading.
This is called spoofing/jamming. Spoofing is when you fake a signal or signature. You make radar or GPS think you are in a location when you aren’t. Bombers use it to make you think there are more bombers in the air than what are actually in the air, for instance, or to make you think you are in one place, but you are actually 500 miles away. You can spoof anything that receives a signal - radar, GPS, RF, maybe even infrared. Infrared would be tough (heat signature of a physical object).
Jamming is when the frequency you are monitoring is receiving a signal of a strength greater than the one you are trying to receive. If your CB radio is more powerful than another guy’s, and he leaves his mike open on Ch. 17, then good buddy with the weaker radio has to pick a new channel and cell phone the guy he was talking to in order to get him to move to the new channel.
The GPS system has already got spoofing countermeasures built into it, both at the transmission and the reception system levels, allowing military and defense to effectively use GPS in a time of active electronic measures. Doubt seriously that it is bulletproof, and my guess they spend a lot to keep it state of the art.
For civilians, the receiver-side countermeasures may not necessarily be there.
How much of a real threat is this, and could it bring down a plane? Not very likely, unless you have VERY bad weather, AND North American civilian aviation radar and military radar goes down, IFF (International Friend or Foe), plus ILS goes down (Instrument Landing System).
All civilian commercial passenger aircraft squawk (transmit) a code as part of IFF or International Friend or Foe. IFF provides anyone with an IFF receiver to verify that the aircraft is actually the one you saw you are.
Without GPS, ground based flight operations can use a combination of radar and IFF to vector you in by regular radio frequency communications. In bad weather, Instrument Landing System uses signals generated by ground-based flight control to ensure the aircraft can land safely.
So, if the signal is low, meaning you have to be on board, then the pilot would have to use back up means to land safely.
As such, this device, if it is low power, is useful as a way of harrassing people in cars with GPS, or with handheld GPS receivers.
I can see GPS spoofing being used to make ground forces think they are in one place when they are in another, but then you have map and compass, don’t you?
Your comment that there are currently no GPS approaches at commercial airports is not true. Almost every commercial airport has GPS approaches. The are called RNAV (GPS) or RNAV (RNP) approaches. I work in the section of the FAA that designs and develops instrument approaches. The trend is for more and more airports, commercial and general aviation, to have increased RNAV approaches published. They get much lower minimums than conventional non-precision approaches, not as low as an ILS, but pretty close.
Its already been tried against the USAF with military grade jammers. Didn’t work. And the emitters sing “Target” to anti-radiation missiles...
What’s RNAV got to do with GPS?
We have had RNAV long before the first satslite ever went up!
That is true. I remember during the 70’s RNAV was the new thing in aviation and the FAA was pushing RNAV routes using INS. Unfortunately, not enough aircraft had INS to make development of RNAV routes worthwhile. So it sort of died out until GPS came along and the FAA resurected the term RNAV and applied it to procedures using GPS.
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