可控震源记录中的脉冲噪声分析

噪声分析一直是地震资料信噪比得以改善的重要基础方法。可控震源向地下输入瞬时低能量信号,易受到可控震源系统内部以及背景中的瞬时脉冲噪声(如电噪声、震动噪声等)的干扰。用于提取有效信号的相关检测方法将脉冲噪声的干扰范围扩大,严重影响了对可控震源有效信号的提取。为了从理论上分析脉冲噪声对可控震源相关记录的干扰,通过仿真实验,系统分析了单点脉冲和多点脉冲噪声对相关记录中可控震源信号的干扰程度和特点。结果表明,可控震源相关记录中的信号主要受脉冲噪声强度、所在时间位置以及可控震源非相关记录脉冲点数比例三方面因素影响,脉冲噪声所占记录的比例大于2.5%且平均强度高于100时,相关检测后的可控震源信号会完全被噪声淹没。

Analysis of the Pulse Noise in Seismic Vibrator Record

Noise analysis is always the important basic method to improve the signal-to-noise ratio of seismic data.Seismic vibrator system emits instantaneous low energy to the underground,so its record is easier to be disturbed by the pulse noise from interior of vibrator system and background.The cross-correlation detection method,which is used to pick signals,can not suppress this kind of noise,and it even widen the noise level seriously.To study pulse noise interference,the authors analyze the impact and characteristics of the record by the single pulse and multi-point pulse noise in theory and simulation. The results showed that the interference is mainly depended on the strength of the impulse noise,the position time and proportion of pulse noise.When 2.5% pulse noise is mixed into vibrator non-correlated data with average intensity is 100,the vibrator signal would be submerged in correlated data.