February 16, 2012: For the seventh time India successfully tested its anti-missile system, intercepting a Prithvi ballistic missile. The AAD interceptor missile was fired from an island 70 kilometers off the coast. The system uses two types of interceptors. The Prithvi Air Defense (PAD) missile is the larger of the two and is used for high altitude (50-80 kilometers up) interception. The short range Advanced Air Defense (AAD) missile is used for low altitude (up to 30 kilometers) intercepts. The two missiles, in conjunction with a radar system based on the Israeli Green Pine (used with the Arrow anti-missile missile), are to provide defense from ballistic missiles fired as far as 5,000 kilometers away. This will provide some protection from Pakistani and Chinese missiles. A third interceptor, the PDV, is a hypersonic missile that can take down missiles as high as 150 kilometers and is still in development. India is the fifth nation to develop such anti-missile technology.
The Indian system has been in development for over a decade. Ten years ago India ordered two Israeli Green Pine anti-ballistic missile radars. That equipment was used six years ago in a successful Indian test, where one ballistic missile was fired at another, incoming, one. The Israeli Green Pine radar was originally developed for Israel's Arrow anti-ballistic missile system. Arrow was built, in cooperation with the United States, to defend Israel from Iranian and Syrian ballistic missiles. India has since developed, with Israel, the Swordfish radar, which has similar capabilities to the Green Pine and has been operational for two years. Swordfish is part of a system that integrates data from satellites and other sources in order to detect and track incoming missiles.
The interceptor missiles and the fire control systems were designed and built in India, although more Israeli technology may have been purchased to speed things along. India wanted to buy the entire Israeli Arrow system but the United States refused to allow the sale (which involved a lot of American technology). The Indian ABM (Anti-Ballistic Missile) system is supposed to become operational in two years.
China and Pakistan could only defeat the Indian ABM defenses by firing more missiles at the same time than the Indians could handle. It's also possible to equip warheads with decoys in an attempt to get the interceptor missile to miss. Israel has technology designed to deal with these decoys and India can probably purchase that. But against an overwhelming number of incoming missiles, some are going to get through.