Fast radio burst detection in the presence of coloured noise

In this paper, we investigate the impact of correlated noise on fast radio burst (FRB) searching. We found that 1) significantly increases false alarm probability; 2) signal-to-noise ratios (S/N) positives become higher; 3) also affects pulse width distribution positives, and there will be more with wider width. use 55-hour observation for M82 galaxy carried out at Nanshan 26m telescope to demonstrate application modelling. The number candidates parameter can reproduced modelling noise. discuss a low S/N candidate detected in observation, which method evaluate probability presence noise.Possible origins are discussed, where two possible pictures, an M82-harbored giant cosmological FRB, both compatible observation.