posted on Jun, 9 2012 @ 01:30 AM
reply to post by DesertWatchdog
They need to swing the dishes for dynamic RCS, i.e. track the plane. With a phased array, they can electronically swing the beam, which is much faster
than mechanical steering. Now a good question is does the beam forming have enough foo that they can switch from side to side of the tower without
loosing track? Or do they have to rotate the tower a bit to keep track. I'm guessing the latter. That is, they use one side of the tower, steer with
beam forming, and rotate as needed. Then each side of the tower could be set up for different frequencies. What ruins that theory is all the sides of
the tower look the same.
Of course, this is just speculation on my part, with a bit of science to back it up.
I looked around youtube for a decent explanation of phased array radar. No luck. Here is one from the NWS:
The theory behind beam forming is very old. The problem was it was difficult to do prior to the creation of high speed data converters and digital
delay. [Phase is just an angular measurement of time delay based on the frequency.] If you look at the history of applied beam forming, at least as I
have observed it, it started with sonar. They used towed arrays since the spacing between elements is a function of the frequency. With sonar. that
means a lot of real estate. Next came ultrasound, then on up the frequency food chain to radar as data converters and computers/DSP got faster.
Here is a towed array sonar: