It 
is known that initial data for interpretation of results of research of 
structure of a seabottom by means of an acoustic profile recorder is profile 
chart – a dependence of capacity of reflected signal on a delay (depth) along a 
line of measurements. Using in profile recorders coherent broadband signals, 
digital registration of a full signal opens use possibility, in addition to 
capacity (amplitude) of received signal, also spectral characteristics of the 
reflected signals for research of structure of a sea ground. 
 
Keywords: 
acoustic profile recorder, profile chart, coherent broadband signals, spectrum 
chirp modulation.