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NC SC inaes* .dent Research 



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REFLECTION AND SCATTERING OF ACOUSTIC RAYS '„G:.:?UTED FOR PARABOLIC ICE KEEL MODELS 



"2. PEF1SONA1. Aun-oR(S) 



D F. Gordon 



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•8 SU8JEC 



'ERMS 



,\.-c!:c acoustics 

 Acoustic p opigation 

 Ray theor, 

 Sea ice „ 



^eflect'on coefficients 

 Scattering coefficients 

 Ice keels 



FT 



•S A6S~RAC~ £imji«n<<aK<ii>M*«a>waii 



Coefficients are computed for rav reflection and scattering from a model of a set of \et\s The model is a collection of parallel ice 

 keels that are of parabolic cross s<cnon The size of the keels and the spacing between S;m are drawn from random distributions The 

 keels are also widened by a random factor 10 simulate oblique incidence on nonparalle' k .els Rays are permitted to reflect from and 

 refract through keels according to tbe'Dterfsc: properties between fluids and elastic soli-iS. A large number of tays are directed toward 

 the keel mc^el and upen emergence a-e vorted into angular bins to determine scattenng nrength versus direction Scattering coef'icients 

 have a d irnnant lobe near the iicu'.ir dn*cur>n. This is shown to result from the shape ,'i the curve of reflection versus gr ung angle 

 Very .i'.ie backscatter occurs, a result of t!K limited slope angle of the parabolic keci rrodels ,V 



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