[3F1] Noise reduction for pipeline inspection utilising the split-spectrum processing method
K Pedram¹ and M Ghafourian²
¹University of Greenwich, UK
²Brunel University London, UK
The guided wave testing (GWT) technique is widely used in various industrial sectors to inspect pipelines where structural integrity is a concern. GWT enables the inspection of long lengths of pipes from a single location using transducers positioned circumferentially around the pipe. However, the received signal is typically degraded and noisy due to the dispersive propagation and multi-modal behaviour of the signal, reducing the sensitivity to small defects and limiting the inspection range. As a result, identifying small defects is particularly challenging, especially in coated and buried pipelines where attenuation rates are considerably higher than those for bare pipes. This paper proposes a novel solution to address this issue by utilising an advanced signal processing method called split-spectrum processing (SSP) to reduce the level of coherent noise and improve spatial resolution. The optimum parameters of SSP have already been identified for bare pipes. In this study, the proposed method was experimentally compared with the conventional approach for a coated pipe. The results illustrate that the proposed method significantly increased the signal-to-noise ratio (SNR) and spatial resolution of GWT, enabling the detection of small defects in coated pipelines. The proposed method can potentially improve the reliability and accuracy of GWT inspections, ultimately contributing to better pipeline maintenance and safety.
Keywords: signal-to-noise ratio, split-spectrum processing, ultrasonic guided waves.
Keywords: signal-to-noise ratio, split-spectrum processing, ultrasonic guided waves.
