TRAVEL-TIME VARIABILITY OF SIGNALS PROPAGATING ALONG INDIVIDUAL RAYS IN A SHALLOW SEA

Measuring travel times of signals propagating along individual rays in a sea waveguide is considered. It is shown that a measuring procedure that uses a maximum location of an envelope of the correlation functi on leads to less accurate estimates than one that uses a carrier phase of the correlation function when output signals of a filter matched w ith the emitted signal are not completely resolved. Data obtained by m eans of both approaches used to process signals propagating along a fi xed 30-km path in a shallow sea are presented.