Quote:
Originally Posted by Soundy
Here's the thing: RADAR doesn't tell anyone what plane it's showing, it just shows an object. They could have picked up a different plane on a similar course and an operator mistook it for the airliner in question.
In fact, there seems to be a little confusion as to exactly how RADAR works: all it does is send out a pulse of radio waves, and IF some are reflected back, it calculates the distance the object is by the time it takes the signal to return. Speed toward or away from the array can be determined by Doppler shift; speed perpendicular to the array can be determined by position change between sweeps.
As has been already noted, civilian RADAR has an effective maximum distance of 120 miles or so - this is because radio waves disperse over distance... same as shining a flashlight on distant trees. The further the object, the weaker the signal, the less reliable it gets. You can get more range with a tighter beam, but at the expense of coverage area and only being able to scan a small area (picture a flashlight you can focus from a wide beam to a narrow spot).
The plane's own RADAR systems have nothing to do with their tracking on the ground; those are there to show the plane's crew what's around it in the sky.
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Not 100% true there Soundy. Your explanation of Radar is spot on but there are ways for it to correctly identify which plane is which. It all depends on the type of transponder that the aircraft has, be in mode A, C, or S. Mode A; if I remember correctly just fires back a target with altitude to the radar station. Mode C you'll get speed, altitude. Mode S you get pretty much errthang concerning the aircraft.
That being said, the aircraft was, 99% chance, out of any sort of radar converage. Missed a couple mandatory reporting points. Shit went down. It fell out of the sky. Errone dead. End of story.