A Golay sequencer based NDT system for highly attenuating materials

In conventional pulse transmission based ultrasonic measurement systems the signal to noise ratio is constrained by the maximum permissible pulse amplitude which may be applied to the transmitter and the thermal noise generated by the receiver amplifier. By exciting the transmitting transducer with a wideband noise source and performing the cross correlation between the exciting noise source and the receiver output an improvement in signal to noise ratio of 40 dB is possible.