radar

Discussion in 'Homework Help' started by prejval2006, Feb 24, 2007.

  1. prejval2006

    Thread Starter Member

    Oct 25, 2006
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    how do radar distinguish between domestis and fighter planes ?
    how it classifies them??
     
  2. n9352527

    AAC Fanatic!

    Oct 14, 2005
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    Commercial aviation radar is a transponder based system (secondary radar), where the transponder transmit signals to determine the position in space. It's easy to recognise commercial flights from the transponder codes.

    Military radar system is the normal radar system as we know it (reflection based). To recognise the military crafts, there is an IFF system that acts as an ID.

    That was what someone told me anyway :D
     
  3. Papabravo

    Expert

    Feb 24, 2006
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    Traditional reflection radar all by itself can't distinguish one type of target from another. ATC can determine intentions by tracking a target. For example approaching restricted airspace at Mach 2 will cause fighters to be scrambled. At lower speed they might actuially try to talk first before opening fire.
     
  4. mrmeval

    Distinguished Member

    Jun 30, 2006
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    Military use IFF which is Identification Friend or Foe
    http://www.globalsecurity.org/military/systems/aircraft/systems/iff.htm

    Newer miltary fighter aircraft radars can do some discrimination of aircraft type but the pilot will still rely on IFF, speed, and ship, land or larger airframe radars such as AWACS to determine aircraft type.

    Failing those they go poke them with a stick and see if they want to come out and play.
     
  5. JoeJester

    AAC Fanatic!

    Apr 26, 2005
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    IIF isn't used in commercial aviation. As far as the blip on the screen, they all look alike.

    Military transponders communicating with ATC may indicate they are military, but you can be sure that in a battle situation, IIF is used and the codes are changed frequently ...

    Lucky for one ship the pilot recognized it was a U.S. warship. Someone forgot to change the IFF to the proper code du jour. The pilot could have just lit that ship up.
     
  6. beenthere

    Retired Moderator

    Apr 20, 2004
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    The difference between military and commercial radar transponders is that the commercial transponders beacon when illuminated by any search radar. The military ones look for an embedded code before responding.

    It helps, too, when hostilities are ongoing, to make an excluded zone where commercial flights are not supposed to transit. That helps the targeting problem. If it doesn't squawk back, assign it a track number and kill it.
     
  7. Gadget

    Distinguished Member

    Jan 10, 2006
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    As in Iran Air flight 655
     
  8. beenthere

    Retired Moderator

    Apr 20, 2004
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    They were'nt the first - we had birds free from the admiral on Yankee Station back in 1972. Another airliner that wasn't squaking and was transiting a zone where he wasn't supposed to be. If our captain had'nt yelled a lot on the radio, we would have zapped that idiot.

    Never, never, never fly over people with missles who have permission to use them.
     
  9. Papabravo

    Expert

    Feb 24, 2006
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    I guess the pilots and passengers of KAL 007 learned that the hard way. The FP even had a visual on them.
     
  10. beenthere

    Retired Moderator

    Apr 20, 2004
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    Think that was more politics du jour than anything else.
     
  11. Gadget

    Distinguished Member

    Jan 10, 2006
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    Ain't it great. Now all we need is a bit of sex and religion..(not necessarily in that order).
     
  12. beenthere

    Retired Moderator

    Apr 20, 2004
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    Where's the drugs and rock & roll?
     
  13. Papabravo

    Expert

    Feb 24, 2006
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    I missed the politics. We were talking about the ability or lack therof for ordinary reflective radar to distinguish various types of targets. Shooting with the limited information of ordinary radar seems on the same level as shooting with a visual identification based solely on where the target was and what the target was doing. It's got nothing to do with politics just because you say so. Who are you anyway to make such a determination?
     
  14. beenthere

    Retired Moderator

    Apr 20, 2004
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    In the case of the shot-down Airbus, the aircraft was in an excluded zone. The pilot may have decided he couldn't be bothered to obey the restriction - who knows?

    With no transponder squawking for id, the ship captain made the decision to protect his crew and zapped what turned out to be a harmless target. Something in the flight path or profile made him elect to do it. A CAP flight might have been able to do a visual id, but perhaps no fighter aircraft were available at that moment.

    KAL007 was squawking a valid transponder code, and was visually sighted and described by the pilots flying the interception. No military target was ever in the flight path. That act was prompted purely by politics.
     
  15. Gadget

    Distinguished Member

    Jan 10, 2006
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    This thread is about distinguishing between military and civilian aircraft, and the airbus incident is a good example of how the system can fail.
    The Airbus was within its correct air corridor in ascent (commercial air corridor Amber 59, not an Excluded zone), it was running 27 mins behind schedule and was squawking the correct civilian IFF (Mode III 6760), but was misidentified as a smaller military F14 in decent (not helped by the the fact that when it took off, an F14 was also on the tarmac and IFF signals may have gotten confused.
    Fortunately these glitches are not common, and the system normally works well, but the case is often used as an example of an over reliance of technology in warfare coupled with a human condition known as 'scenario fulfillment'.
     
  16. Papabravo

    Expert

    Feb 24, 2006
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    About this we disagree. The operational theory of the pilots and the ground controllers was that KAL 007, a civilian 747, was conducting electronic surveillance. This supposition was enhanced by the fact that US spy planes, an RC-135, regularly flew in circles (orbits) near the Russian Air Defense perimeter. I believe it's true that the Russian pilots required direct orders approved at a high level in order to fire. Just because they had that approval does not make the decision to fire a political one. The fallout of the decision was of no benefit politically.


    The following link may be helpful for the references.
    http://en.wikipedia.org/wiki/Korean_Air_Flight_007

    In my mind there are three possibilities in Air Defense. It's one of ours, it's one of theirs, or we're not sure. In two out of three cases when pressed for a decision the answer will be to shoot first and apologize later. As over the horizon weapons become more common the reliance on non visual means of identification represents an increasing risk to civilian aviation in many parts of the world, and puts enormous pressure on flight crews to do their jobs with extreme precision and accuracy.
     
  17. beenthere

    Retired Moderator

    Apr 20, 2004
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    There might be some ignorance on my part - I accepted the official version that they took off with an offset in their starting coords, so the flight computer ran their route inside Russian airspace.
     
  18. Papabravo

    Expert

    Feb 24, 2006
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    There are at least two official versions. I was speaking of the "official Russian version". It is also my understanding that an error in the programming of the INS(Inertial Navigation Ssytem) was the proximate cause of the intrusion into Soviet airspace.

    None of which was discussed by the Soviet pilots and their ground controllers.
     
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