US keeps track of N Korean missile tests
Publicly, US President Barack Obama and senior officials in his administration berated North Korean leader Kim Jong-il recently for firing 11 ballistic missiles eastwards, into the Sea of Japan - four short-range missiles on July 2 and seven medium-range missiles on July 4. It was the biggest North Korean missile barrage seen so far.
Secretly, US officials informed on missile defences were pleased, for two reasons. First, the elaborate US missile defence in place in Japan, Alaska, California, Hawaii, aboard navy ships, and in satellites was severely tested and worked well. In particular, the fusion of data from sensors based on land, at sea and in space produced swift, clear images of what the missiles were doing.
Second, US intelligence gathered information about the missiles that otherwise could not have been discovered. 'We learned an incredible amount about where exactly North Korea is in their long-range missile development programme,' said an official in Washington. As North Korea has only ageing radar, he doubted it 'learned anything close to what we learned about their tests'.
The officials said North Korea's missiles were fired from mobile launchers but the US had been able to track them with satellites and reconnaissance aircraft.
In addition, the North Koreans have become more skilled at disguising launch sites with shields like medieval armour through which radar cannot see. The US, however, has found undisclosed ways of piercing that camouflage.
The missiles were sighted by US radar in northwestern Japan near the remote village of Shariki, then picked up by radar on Shemya in the Aleutian chain of Alaska and another encased in what looks like a giant golf ball aboard a seagoing base in the mid-Pacific. A satellite and an Aegis destroyer on patrol in the Pacific also tracked the missiles.
Missile data was transmitted to a US command centre at Yokota Air Base west of Tokyo, where much was shared with Japan's Self-Defence Forces. The data went to operations centres in Hawaii, Northern Command in Colorado, Strategic Command in Nebraska, the National Military Command Centre in the Pentagon, and to the situation room in the White House.
Keeping track of the missiles was made a bit easier when the North Koreans spaced out the launches. Joseph Bermudez, a specialist on North Korean military affairs, wrote in Jane's Intelligence Review that on July 2 the launches of the missiles were 40 minutes to nearly two hours apart. They landed in the sea, within 100 kilometres from the shore.
On July 4, the seven missiles were launched about two hours apart and flew a distance of 420-480 kilometres over the Sea of Japan. All suggested the North Koreans had improved the accuracy of their missiles.
The only aspect of missile defence not tested was, obviously, taking a shot at a North Korean missile. The system was alerted to shoot if the sensors had shown a long-range missile heading to a target in Japan or the US.
Richard Halloran is a former New York Times foreign correspondent in Asia and military correspondent in Washington