Patent ID: 7106657
Filing Date: 2006-09-12
Classification: G01S,Y10S

Abstract:
1. A digital sounder module comprising: a sonar transducer for transmitting an acoustic sonar wave at a selected frequency and pulse rate and for receiving echos of said transmitted acoustic sonar wave reflected from objects and for converting said received acoustic sonar wave into a first electrical signal; a band-pass filter for providing a first wide bandpass filtration on said first signal to produce a second signal; an amplifier for controlled amplification of said second signal to produce a third signal, said third signal being an amplified carrier wave; an analog to digital converter for receiving said amplified carrier wave, a rate at which said amplified carrier wave is converted to a digital signal by said analog to digital converter provides a harmonic sub-sampling, and said analog to digital converter transforms said amplified carrier wave into a digital intermediate frequency; a programmable logic device, said programmable logic device implements a non-coherent windowed in-phase/quadrature (I/Q) detector and performs a Fourier transform of the intermediate frequency sonar return signal, said Fourier transform converts the intermediate frequency sonar return signal into a complex return signal which includes a real value that is an in-phase detected signal and an imaginary value that is a quadrature detected signal, said programmable logic device then multiplies the complex return signal by a programable Kaiser window filter, said programmable Kaiser window filter sets said bandwidth and said frequency, said programmable logic device provides a microprocessor, said microprocessor provides an output for a display of said reflected echos.