Microcomputer-based digital pulse compression system for ultrasonic NDT

A microcomputer-based digital pulse compression system suitable for ultrasonic non-destructive testing applications is described. By utilizing software for code generation as well as for correlation processing, this approach possesses a high degree of flexibility accommodating different types and lengths of transmission codes. The implemented system, which employs bi-phase modulation of the transmitter waveforms with m-sequences and Golay codes, provides significant signal-to-noise ratio enhancement with zero range sidelobes. Results from the operating system are in good agreement with theoretical predictions and confirm the feasibility of the method.