Israel recently constructed two 1,300 foot (400 meter) antenna towers next to its nuclear weapons development facility at Dimona. Israel expects this to be a major target of any Iranian attack, partly because it is out in the desert and such action is unlikely to kill any Israeli Moslems. The government won't say what the towers are for, but insists they are not for an offensive weapon. There is speculation that the towers are part of some new sensor system. If so, the two towers would be the largest ever built for such purposes.
Israel has been determined to establish the best possible defenses against Iranian ballistic missiles. This includes a recently installed American "X-Band Radar," a system similar to the radars used in Aegis anti-aircraft systems on U.S. Navy ships. This technology uses thousands of small radar transmitters to get detailed information on objects out there, and many objects at once. The missile detection radar has, in addition, the ability to see activity at long distances (in some cases, up to 5,000 kilometers out.) This missile detection radar can not only see a missile being launched, but it can tell the difference between decoys, and real warheads, after the missile has exited the atmosphere and sent its payload plunging back to earth.
But many Israelis officials are not happy about this American X-Band radar, because it is on loan and manned by U.S. personnel. This means the U.S. has a record of all air activity over most of Israel. Apparently there are things up there that some Israelis would prefer to keep secret, along with what the two Dimona towers are for.