North Korea is drastically expanding a missile launch site in Musudan-ri, North Hamgyong Province, and has changed the shape of warheads to improve missile accuracy.
"The North is building a new launch site designed for massive rockets in Musudan-ri," a South Korean missile expert said. "They're expanding the assembly facility there by 28 m so that they can assemble two long-range missiles simultaneously."
South Korean authorities believe that the new launch facility is bigger than the missile test site in Tongchang-ri, North Pyongan Province from which the North's space rocket was launched last year. They base their conclusions on a flame-passage device and a huge fuel tank there.
The expert said the accuracy of the North's missiles is likely to improve through the use of triconic instead of simple conic warheads, a change of shape which does not reduce the weight.
Triconic warheads were first used for the improved version of the Rodong missile in 2000 and are now also being used for medium and long-range missiles, he said.
Iran's Shahab missile, which is based on the North's Rodong missile, also has a triconic warhead, which shows connections between the two countries, the expert claimed.
The North has deployed around 1,000 ballistic missiles -- about 700 Scud-B/C missiles with a range between 300 and 500 km and some 300 Rodong missiles with a range of 1,300 km. The regime has also conducted about a dozen tests since 2005 of short-range missile with a range of about 120 km.