North Korea has started testing missile-tracking radar and other monitoring equipment at its northeastern missile test site following its announcement of a satellite launch, a Seoul daily reported Friday. ''North Korea has made preparations for the launch of Taepodong-2 (missile) at the Musudan-ri test site and started test-operation of equipment related to missile tracking and control such as 'Fire Work' radar,'' a South Korean government source told the Chosun Ilbo newspaper.