A Direct Numerical Imaging Method for Point and extended Targets Wang Hongxia Department of Mathematics and systems science NUDT 2011-06-21
A Direct Numerical Imaging Method for Point and Extended Targets Wang Hongxia Department of Mathematics and Systems Science, NUDT 2011-06-21
Outline 1 Introduction and motivation .A 2. Direct imaging for point/extended targets ◆ Algorithm Numerical results 3 Multiple attenuation in seismic signal 今4. Future work (過两科学大季 A Direct Numerical Imaging Method National University of Defense Technology
A Direct Numerical Imaging Method Outline ❖ 1. Introduction and motivation ❖ 2. Direct imaging for point/extended targets ◆ Algorithm ◆ Numerical results ❖ 3. Multiple attenuation in seismic signal ❖ 4. Future work 2
l。 Introduction o Probing a medium using waves to detect and image targets is useful in Medical applications nondestructive testing, mine detection, target detection… 气枪 检波器 防科学时太季 A Direct Numerical Imaging Method National University of Defense Technology
A Direct Numerical Imaging Method 3 1. Introduction ❖ Probing a medium using waves to detect and image targets is useful in ◆ Medical applications, nondestructive testing, mine detection, target detection …
l。 Introduction o Imaging is to resolve an inverse problem nonlinear ill-posed problem 骣 CD 0,Dy+k2y=0 ☆ Methods Iteration regularization Direct imaging algorithm MUSIc (過两科学大季 A Direct Numerical Imaging Method 4 National University of Defense Technology
A Direct Numerical Imaging Method 1. Introduction ❖ Imaging is to resolve an inverse problem ◆ nonlinear, ill-posed problem ❖ Methods ◆ Iteration + regularization ◆ Direct imaging algorithm (MUSIC) 4 2 2 2 1 0; v t y 骣ç ¶ ÷ çD - = ÷ ç ÷ ç桫 ÷ ¶ 2 D + = y y k 0
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 Technology
A 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