HYDROACOUSTIC DOPPLER LOG WITH MULTI-ALTERNATIVE ECHO SIGNAL FILTRATION ALGORITHM BASED ON USE OF KALMAN FILTER BANK Russian patent published in 2012 - IPC G01S15/58 

FIELD: physics.

SUBSTANCE: hydroacoustic Doppler log has a four-beam hydroacoustic antenna, an antenna switch, a radiation switch, an antenna matching circuit, a power amplifier, a received signal switch, a differential receiver, a programmable amplifier, a band-pass filter, an analogue-to-digital converter, a digital heterodyne, a digital decimation filter, a UART controller and RS-232 and RS-422 transceivers. The log additionally has a DSP processor, to the output of which data are transmitted from the digital decimation filter from four channels for measuring velocity of an object (nose, stern, portside, starboard), through which the echo signal is processed via multi-alternative filtration technique which uses a Kalman filter bank and is aimed at evaluating the parameter of the model of the echo signal corresponding to the value of the velocity of the object, with limiting error of not more than 0.1 knots for a time of not more than 4 s, and the resultant value of velocity of the object is output through the UART controller and RS-232 and RS-422 transceivers to an external user.

EFFECT: simple and cheap design of the log while increasing measurement accuracy.

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