Word noise is used in seismic as a generic name for unwanted components of seismic signals.Noise could be a relatively persistent vibration of the ground, due to a multitude of causes which are of no use in seismic interpretation.The noise can be classified as
Coherent Noise is organized, predictable or repetitive in pattern,They can be traced across atleast few traces.Few examples of coherent noise are given below:
Direct and near surface waves:
A.Low velocity, marine or land traffic, and source generated noise
B.Medium to high velocity near surface refraction
In addition diffractions (point sources) and compressional converted shear waves can also lead to coherent noise.
Incoherent noise is dissimilar on all traces and its not possible to predict what traces would be like on the basis of nearby traces.Incoherent noise is also referred as random noise.Most of the Incoherent noise are generated by any external source such as Human activity, animals or wind etc.