Ground roll and polarization

Ground roll is the major source of coherent noise on land seismic data. It is current practice to attenuate ground roll through the use of geophone arrays in the field, and by velocity filtering during processing. However, data recorded using multi-component geophones provide an additional means of attenuating the ground roll through polarization filtering. The basis of polarization filtering for roll attenuation is to utilize the phase difference between the components. Body waves are assumed to exhibit linear motion (in phase) whilst ground roll is assumed to exhibit elliptical motion (out of phase).