2. Direct imaging for point targets the response matrix P()=鵝() PML N′N ☆ The reflected signal r(t=P(te(t) e,):()L,() transducers =P()*).2(),L,:、( 防科学时太季 A Direct Numerical Imaging Method 5 National University of Defense TechnologyA Direct Numerical Imaging Method 2. Direct imaging for point targets ❖ The response matrix ❖ The reflected signal 5 ( ) ( ) ij N N P t p t ´ = 轾犏臌 r t P t e t ( ) ( ) * ( ) = v v i.e. 1 2 1 2 ( ), ( ), , ( ) ( ) * ( ), ( ), , ( ) N N r t r t r t P t e t e t e t 轾犏臌 = 轾犏臌 L L