where 



/oo 

 P(t,T)e"^'^'^dT 



— 00 



Is the scattering function. 



Neither measurements nor a comprehensive theoretical 

 analysis of the complete doppler spectrum or scattering 

 function for a random sea surface appear to have been 

 attempted. Published Investigations have considered either 

 the scattering cross sections I.e., the mean power of the 

 backscattered pulse 



U) 



a = /j( T(t,t,u)dt d 



and Its doppler decomposition 



f(co) =jT(t,t,w)dt , 



both of which average out the travel time Information (and 

 can therefore be determined from CW-type measurements), or 

 alternatively the mean pulse power 



I(t) = JT(t,t,w)daj 



as a function of delay time, which makes no use of the 

 doppler Information. 



Cross-section and doppler measurements are normally 

 made at finite angles of Incidence, whereas travel-time 

 data has been obtained largely from altimeters operating 

 at near normal Incidence. Different scattering models are 



25-32 



