DISTANCE ASSESSMENT USING SOUND SIGNALS Russian patent published in 2016 - IPC G01S3/82 

FIELD: measurement equipment.

SUBSTANCE: group of inventions relates to metrology, in particular, to acoustic devices for distance measurement to an object. The device comprises a test signal generator, a modulator, a parametric loudspeaker, an ultrasonic signal demodulation device, a sonic frequency signal reception device, a distance assessment circuit. The distance calculation circuit generates estimate in response to comparison of registered signal of sonic frequency and test signal of sonic frequency for detection of delay corresponding to total length of the trajectory. At the same time the test signal generator is made with the capability to calculate estimate of reflected sound signal. Estimate of the reflected sonic signal may be detected as corresponding to the sonic signal, which is generated as a result of non-linear demodulation of the test signal of sonic frequency in air. The difference between estimate of the reflected sonic signal and test signal of sonic frequency characterises non-linearities of sound trajectory. During distance assessment, they calculate maximum of correlation between the recorded signal of sonic frequency and assessment of the reflected sonic signal.

EFFECT: increased accuracy and simplified procedure of measurements.

15 cl, 11 dwg