People do not know what they are talking about. These people go on what they think can happen, and not what actually happens.
The various "Jamming" of GPS that you point to is based on huge signal noise sources and a great deal of power and do not "confuse" the system as you seem to think (ie:false readings) but simply overwhelm the GPS signal itself. Such jammers are easily located and destroyed IF you're actually shooting already. Unfortunatly it is not so cut and dried when there isn't an actual "shooting-war" going on. (Your example of North Korea) Point of fact most "GPS" guidance systems can NOT recieve GPS signals in any direction EXCEPT from "above" them so the ONLY way to "interfer" with a GPS signal is either to push out enough noise and power to overwhelm the signal (which paints a huge target on yourself and gets one killed rapidly) or to have a weaker, more directed "source" with the SAME frequency and input protocals as the original signal source somewhere "in-between" the GPS satillite and the reciever.
To which you provide the answer of the "enemy" putting up satellite(s) to do just that...
Which shows you don't understand how GPS works, or the difficulty of doing such a thing. GPS satellites are in Low Earth Orbit and there are hundreds of them. Now, while I don't have the exact numbers a simple check tells me that CIVILAN GPS systems, for example a hand held or car unit uses at least THREE GPS satellite signals in coordination to find it's location. A MILITARY system would use many more than that. Now in order to "spoof" a UAV or UCAV, (let alone a GPS guided bomb) you would have to intercept and over-ride each and EVERY one of those signals (satellites) with one of your own. So you now have to launch a complete GPS satellite network simply to try and interfere with "my" GPS network, but worse yet I don't need to have anything BUT a signal and a known orbit if I have ANY type of INS system and/or I "know" where I started, and where I'm going to guide me to the general area of the target!
And you have to have enough satellites in orbit for me to have multiple signals (all with the proper protocol, wave-length, and pulse train, etc) over my entire flight time. And they HAVE to come in at the proper "angle" to the reciever so you can't simply put a big satellite into GEO because it won't "move" the proper way a LEO satellite will!
Vulnerability of UAVs and remotely GPS guided weapons
Some inputs regarding GPS.
The article that you have sited is mostly correct with some exceptions.
1.GPS system uses
4 satellites to find it's position rather than three.Three satellites theoretically could triangulate its position but when signals are travelling at speed of light,even small variation like that of a microsecond could cause an
error of 300 meters.Thus the requirement of four satellites.
2.The receiver compares time reading transmitted by clocks on GPS satellites with it's internal clock and calculated it's position using the lag to determine it's position.
3.A GPS system consist of
24 satellites in an orbit at 55[SUP]o[/SUP] azimuth.
Only US (GPS) and Russian (GLONASS) is a GPS system with global coverage.Chinese are coming up with COMPASS and Europeans with GALILEO.Apart from this INDIA is coming up with GAGAN which would be a regional GPS system with 12 satellites covering only Eastern Hemisphere.
4.The error in signal transmitted by satellites is to the tune of 20 meters horizontally and 30 meters vertically.The source of error in GPS system are- Solar particle showers,ionosphere,water vapour in troposphere and the biggest being water vapour in lower troposphere.
5.To achieve acurracy of within 1 m horizontally and 2 m vertically,a GPS system uses 2 receivers.One receiver is with the projectile and another is at a fixed location on ground.The one with fixed location calculated error for the region and transmit it to other receivers which corrects their position based on it.
6.As far as my knowledge goes,
most of the cruise missiles use Inertial navigation systemwhich does not require outside Inputs at all. Even if a missile is using a GPS system,there would also be a self contained Inertial navigation system in missile.Reason being that GPS signals could be jammed and also that there would not be second transmitter and job of adjusting the trajectory would be done by INS while passing over predetermined coordinates.I do not have knowledge on this so someone who works with military may be a better source.
7.GPS signals are not received from Top only but from all the directions.
So in order to redirect a GPS guided missile,
1.Enemy has to know about transmitting frequency.This is a relatively easy job.
2.Enemy needs to have a copy of OS.Military systems are usually not run on windows or mac's.Enemy need to have a copy of OS which GPS system is using.To get this enemy need to have a mole at least among middle level officials.Also OS is not written by one person so if espionage is being done from source,it need to have a large number of moles.The problem for espionage from middle level is that the operator is spying may not have access to whole of OS but just the portion pertaining to his work.
3.Enemy need to have codes and passwords for that particular day so need to have moles among operators.
4.After this has been achived,Enemy need to have a way to mimic GPS satellites,for it at least 4 satellites with highly accurate clocks onboard are needed.
5.If a missile is hacked it could be made to crash or malfunction but for redirecting,missile need to have a physical ability to be redirected.
These are in the realm of fantasy and so difficult that even countries more resourceful than Iran have said FK it we would make a system to shoot down missiles.
In short Iranian claim is troll and even a Undergraduate could see through this bullshit.
Iran is disclosing and hyping some technologies as a deterrence, so enemies would think twice before attacking. That said, Iran isnt disclosing all its capabilities, quite some tech. remains secret. There were many interviews with Iran's generals claiming they have plenty of secret tech "in the sleeves".
No when your enemies know that you claim are more fictional than 1001 Arabian Nights.
With a post like that .. you wanted to show every one how rude you can get !
SC is the Shia from Canada ! .... now be upfront and claim that you posted without your " religious compulsions"
People a lot more learned than me are trying to tell you some thing in this thread, why don't you read all posts.
SC is the major fundamentalist troll here (another being Zarvan).His answer to every problem is look inside Quran and try to argue with him and you would be dubbed as muslim hater.
Arguing with him is pointless.
You should not expect much logical reasoning from a person who belives that human are made from Clay and sperm.
