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

中文翻译：

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存在有色噪声时的快速无线电突发检测

在本文中，我们研究了相关噪声对快速无线电突发 (FRB) 搜索的影响。我们发现（1）相关噪声显着增加了误报概率；（2）误报的信噪比（S/N）变高；(3)相关噪声也影响误报的脉宽分布，脉宽越宽误报越多。我们使用南山 26m 射电望远镜对 M82 星系进行 55 小时观测来展示相关噪声建模的应用。可以通过相关噪声的建模来再现误报的候选数量和参数分布。我们还将讨论在观察中检测到的低 S/N 候选，为此，我们演示了在存在相关噪声的情况下评估误报概率的方法。讨论了候选者的可能起源，其中两个可能的图片，一个 M82 的巨脉冲和一个宇宙快速射电暴，都与观测相符。