METHOD OF ESTIMATION OF ICE CONDITIONS FROM SUBMERSIBLE VEHICLE Russian patent published in 1994 - IPC

FIELD: acoustic detection and ranging of objects. SUBSTANCE: method of estimation of ice conditions from submersible vehicle includes radiation of high-frequency acoustic signal modulated by amplitude by low-frequency signal by harmonic law with modulation factor m (0.5 less/equal m less/equal 2) towards water surface, reception of echoes on frequencies F and 2F, raising of echo on frequency F to second power, multiplication of squared echo on frequency F and of echo on frequency 2F, averaging of obtained signal in time, determination of presence of ice by polarity of first resulting signal and of ice thickness by time of lagging behind of averaged signal of polarity opposite to first one. EFFECT: enhanced authenticity of estimation of ice conditions. 3 dwg