Geophysical diffraction tomography using waveform as projection

Abstract

I n o r d e r t o i m p r o v e t h e p r e c i s i o n a n d r e s o l u t i o n o f t h e r e c o n s t r u c t e d i m a g e i n the geophys ica l tomography , the i sochronic p l a n e d i f f r a c t i o n tomography based on the generalized Radon transform is proposed for geophys ica l exp lora t ion , us ing waveform as p r o j e c t i o n . I n t h i s m e t h o d , t h e s c a t t e r e d f i e l d i n t h e t i m e d o m a i n c a n b e r e l a t e d t o t h e v e l o c i t y p e r t u r b a t i o n b y a g e n e r a l i z e d R a d o n t r a n s f o r m ( G R T ) u n d e r g e o m e t r i c a l op t i ca l approx imat ion . There fo re , based on th i s GRT, the a lgebra ic equa t ion sys tem for i n v e r s i o n c a n b e e s t a b l i s h e d b e t w e e n e a c h p o i n t o n t h e w a v e f o r m a n d m e d i u m p a s s e d through by the i sochron ic p lane cor responding to th i s po in t . Then , ART and SIRT a re used to so lve these equa t ions fo r invers ing v e l o c i t y i t e r a t i v e l y . The numer ica l r e su l t s applied to cross-holes tomography show that the new d i f f rac t ion tomography method prop o s e d i n t h i s p a p e r i s e f f e c t i v e t o i n v e r s e t h e w a v e f o r m d a t a a n d t h e p r e c i s i o n a n d r e s o l u t i o n i n t h e r e c o n s t r u c t e d i m a g e a r e h igh .