The physical principles of the hydroacoustic wavegraph’s operation, which is the facility for measuring of hydro conditions on the seadrome’s aviation water area, are considered. The device includes channels for both measuring the parameters of sea waves in the wave recorder mode by the "inverted" echo sounder method and processing Doppler information to search for the general direction of propagation of the surface wind wave due to oblique echo sounding of the agitated interface from the bottom of the water area. A distinctive feature of the wave recorder is the use of a bottom receiving-emitting antenna assembly of an original design, which allows the simultaneous operation of both channels, moreover, on several working ultrasonic signals due to the use of nonlinear acoustics effects - self-action and self-demodulation. For example, due to the effect of self-action, the spectrum of the probing signal with a frequency is "enriched" with higher harmonic components with frequencies, where is the number of harmonics for which ultrasonic fields have features - the angular width of the main lobe of the directivity characteristic in the radiation mode for each subsequent harmonic is less, and the level of the side field - below. The device can provide registration of sea waves parameters (direction of wave movement, height and wavelength, wave period) for a long time with high accuracy, reliability and stability, which makes it promising for use as part of reference systems.
