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North Korea Jamming GPS Signals In South Korea
Fluffeh writes "North Korea has been looking for new and inventive ways to mess with South Korea. It seems that their missile launch fizzled a bit though, so those wacky folks from the North have bought a few GPS jamming trucks from Russia and are now blocking GPS signals around their city of Kaeson. While Kaeson is around 60 Km inside their borders, the jamming circle is around 100 Km, so it actually covers good parts of South Korea including the airports at Inchon and Gimpo. While no accidents have been caused as yet, it has caused quite some disruption and has made ocean going craft suffer as well due to their heavy reliance on GPS signals."
Noob question here: apart maybe from frequency allocation, is there an international law or equivalent regulation on signal jamming?
The Korean War never ended.
While no accidents have been caused as yet, it has caused quite some disruption and has made ocean going craft suffer as well due to their heavy reliance on GPS signals.
It's amazing how many pilots/captains have completely lost the ability to navigate their vessels without electronics and the problem is made worse by the fact that the infrastructure you need to navigate without it has been neglected or even systematically dismantled in many countries. I have sometimes wondered what effect it would have on a major NATO military maneuver if you specified half way through the war-game that: "The enemy just knocked out several of our GPS satellites, please simulate this by not making any use of your GPS equipment nor any GPS enabled munitions except those that have a fallback mode".
Only to idiots, are orders laws.
-- Henning von Tresckow
We're jammin':
I wanna jam it wid you.
We're jammin', jammin',
And I hope you like jammin', too.
Thanks for the update, Hawkeye.
If you mod me down the terrorists will have won
The US does not jam GPS signals, you're thinking of Selective Availiability which is currently disabled.
http://en.wikipedia.org/wiki/Selective_Availability#Selective_availability
GPS includes a (currently disabled) feature called Selective Availability (SA) that adds intentional, time varying errors of up to 100 meters (328 ft) to the publicly available navigation signals. This was intended to deny an enemy the use of civilian GPS receivers for precision weapon guidance.
SA errors are actually pseudorandom, generated by a cryptographic algorithm from a classified seed key available only to authorized users (the U.S. military, its allies and a few other users, mostly government) with a special military GPS receiver. Mere possession of the receiver is insufficient; it still needs the tightly controlled daily key.
Before it was turned off on May 2, 2000, typical SA errors were about 50 m (164 ft) horizontally and about 100 m (328 ft) vertically.[5] Because SA affects every GPS receiver in a given area almost equally, a fixed station with an accurately known position can measure the SA error values and transmit them to the local GPS receivers so they may correct their position fixes. This is called Differential GPS or DGPS. DGPS also corrects for several other important sources of GPS errors, particularly ionospheric delay, so it continues to be widely used even though SA has been turned off. The ineffectiveness of SA in the face of widely available DGPS was a common argument for turning off SA, and this was finally done by order of President Clinton in 2000.
The power requirements are different.
To jam a signal you need to transmit noise that can drown the original signal, so that the receiver cannot figure out what it is. To transmit fake information, you need a much stronger transmitter because you not only need to drown the original signal but also have your signal be strong enough so that the receiver does not get confused when it receives both signals (the original and yours), otherwise you are just jamming.
Also transmitting fake information requires more complex electronics instead of just a noise generator and a big transmitter.
If you were blocking sigs, you wouldn't have to read this.
This is far from new. My brother is an Apache pilot and has had two tours in Korea. The North periodically jams GPS along the border. They also provide false navigation signals (including encoded identification) for both NDB and VOR near the border. They get a hard on for the potential to create an international incident. They would love to declare the US violated their airspace. Should it happen, of course they would claim their border was violated and neglect to tell you they also caused it.
Pilots receive specific training there so as to double check all navigation signals and to cross check against maps. They are not allowed to use GPS for primary navigation. They're not supposed to use it for primary navigation anyways, but in Korea, along the border, the realistic need is brought to the forefront.
So basically, this is the same stuff they've been doing for two decades. Seriously, nothing new here...aside from the fact that perhaps civilians are hearing about it.
Yes, NK state radio is delivered to each home by wire. And each home has a "radio" set which of course is geared to only connect to this wire, and does not receive any RF signal indeed. In NK not only you aren't supposed to listed other countries' radios, but you technically can't.
And incidentally, this "wire radio" is by design unjammable...
Herve S.
Hell, NK has shelled islands belonging to the South, and is believed to have been behind the sinking of a South Korean Navy Vessel. Lives have been lost due to this, both of which constitute acts of war, yet nobody responded.
That's just the beginning. Abductions of South Korean and Japanese civilians, and probably a few citizens of some other countries as well. The 1983 Rangoon Embassy Bombing and 1987 Flight 858 Bombing. Probable government-level drug-smuggling and similar criminal enterprises.
From a standpoint of international law, North Korea's government level, large-scale counterfeiting of US Currency, just by itself, might be sufficient to constitute an act act of war.
Now that he's finished "Dark Shadows", and in the spirit of "Mars Attacks!", and Edward Scissorhands etc., we really need Tim Burton to do a movie about North Korea. I think he could capture the ethos.
Gently reply
In the US, the FAA is planning to discontinue VORs and omnirange stations, the non-satellite navigational aids that have run aerial navigation for decades. The Coast Guard discontinued LORAN C in 2010. This was done with the concurrence of the Department of Homeland Security, which said it was "not needed for GPS backup."
GPS is a very weak signal, and easy to jam. Satellites put out only 500 watts, spread over half the surface of the planet. LORAN C was transmitted at power levels from 100KW to 4MW, with huge antenna farms. That kind of power is difficult to jam at any distance. VORs and omnis aren't as powerful, but they're usually located at airports, so that when you're close to an airport and need to find the runway, the signal is at its strongest.