Wave propagation in stratified random media - NIST ….pdfVIP

RADI O SCIENCE Journal of Research NBSj USNC- URSI Vol. 68D, No.6, June 1964 Wave Propagation in Stratified Random Media Yung Ming Chen C ontribution From the Division of Mathematical Sciences, Purdue University, Lafayette, Ind. (R eceived D ecemb er 10, 1963 ; r evised January 6,1964) The problem of wave propagation in strat ifi ed m ed ia is reexamined from the stochastic point of view b y introducing the concept of random m edia. For a small inhomogen eity, this problem is investigated by ut ilizing t h e e ffect ive r efractive coefficient of Chen [1964]. For a large i n homogeneity, this problem is treated by subdiv id ing the m edium into many parall el Ilomoge neou s lay er s of random m ed ia and ut ilizing the d eriv ed reflection and trans- mi ss ion coefficients of Chen [1964] . In each case, it is found that the small randomness has no dra stic and un expected effects on thf b f ha vior of the wave motion in the m edia co nsid ered. H en ce, our r eliance on the results obtained by a nonrandom approach is increased. 1. Introduction The subj ect of wave propagation th r ough a non r andom m edium has b een investigated thorough ly by many au th ors [Brek hovskik h, 1960; vVn,it, 1962] . Since, in practice, the properti es of the medium are either impossible to be m easured accurately or subj ected to random variation s due to