Shear wave processing of 3D data requires that the particle motion can be accurately reconstructed from the measurements of the seismic instrument. This requirement cannot be assumed honored on the raw field data: the orientation of the geophones are usually not accurately surveyed, and since the geophone response depends on their largely unknown coupling with the earth, within a single multicomponents sensor the frequency response of each geophone can significantly vary. Using the hydrophone data, we propose a robust method for the QC of the geophones orientations, the spectral calibration of the geophones. The methods is illustrated with synthetic example, and applied to real data.
In the recent past, manufacturers of the seismic instrumentation have provided the acquisition industry with a new design of geophones that can operate in any direction in space with an identical response.