2. Direct imaging for point targets We have M P(w)=a gig k=1 s=(xx)G"(x…x)LG"(x Ey Rank(P(w))=M (過两科学大季 A Direct Numerical Imaging Method 7 National University of Defense TechnologyA Direct Numerical Imaging Method 2. Direct imaging for point targets We have 7 0 0 1 0 0 0 0 1 2 ( ) , ( , ), ( , ), , ( , ) M T k k k k T k k k N k P g g g G G G w t = = = 轾犏臌 å v v v x x x L R ank P M ( ( )) . w =