Dictionary:Redundancy

(ri dun’ d∂n sē) A repetition of information, such as the same measurements made several times (usually in several ways). Redundancy permits the attenuation of some distorting effects. Successive measurements may differ from each other because components other than the objective components differ; thus the objective data will be recorded the same each time and may be distinguished from the varying components. For example, twelve-fold common-midpoint recording involves measuring the reflected energy from a given portion of the subsurface twelve times and hence has a redundancy (or fold) of 12.