▁beam , ▁the ▁scattered ▁intensity ▁results ▁from ▁the ▁inter ference ▁between ▁the ▁amplit udes ▁associated ▁with ▁the ▁various ▁scatter ing ▁paths ; ▁for ▁a ▁dis ordered ▁medium , ▁the ▁inter ference ▁terms ▁are ▁was hed ▁out ▁when ▁aver aged ▁over ▁many ▁sample ▁configurations , ▁except ▁in ▁a ▁narrow ▁angular ▁range ▁around ▁exact ▁back sc atter ing ▁where ▁the ▁average ▁intensity ▁is ▁en hanced . ▁This ▁phenomen on , ▁is ▁the ▁result ▁of ▁many ▁sin us oid al ▁two - w aves ▁inter ference ▁patterns ▁which ▁add ▁up . ▁The ▁cone ▁is ▁the ▁Fourier ▁transform ▁of ▁the ▁spatial ▁distribution ▁of ▁the ▁intensity ▁of ▁the ▁scattered ▁light ▁on ▁the ▁sample ▁surface , ▁when ▁the ▁latter ▁is ▁ill umin ated ▁by ▁a ▁point - like ▁source . ▁The ▁en hanced ▁back sc atter ing ▁re lies ▁on ▁the ▁construct ive ▁inter ference ▁between ▁reverse ▁paths . ▁One ▁can ▁make ▁an ▁anal ogy ▁with ▁a ▁Young ' s ▁inter ference ▁experiment , ▁where ▁two ▁diff ract ing ▁sl its ▁would ▁be ▁position ed ▁in ▁place ▁of ▁the ▁" input " ▁and ▁" output " ▁scatter ers . ▁ ▁See ▁also ▁Back ▁scatter ing ▁alignment ▁( B SA ), ▁a ▁coordinate ▁system ▁most ▁commonly ▁used ▁in ▁rad ar ▁For ward ▁Sc atter ing ▁Al ignment ▁( F SA ), ▁a ▁coordinate ▁system ▁primarily ▁used ▁in ▁opt ics ▁O pp osition ▁sur ge ▁An ▁astronom ical ▁phenomen on ▁caused ▁by ▁the ▁coh er ent ▁back sc atter ▁effect ▁ ▁References ▁▁ ▁* ▁Category : Sc atter ing , ▁absor