The linear character of the polarization of direct P-wave arrival is often used industrially for orientation and processing of offset VSPs but the Pwave polarization method often is not applicable in zero offset VSP due to very low energy of the P-wave first arrivals projection on the horizontal components. It is absolutely necessary to orient the 3 components in true geographic coordinate system or at least into a coherent coordinate system prior to processing for computing dip and azimuth of certain reflector.
This paper present a simple method for estimating the orientation of seismic sensors of zero offset vertical seismic profile (VSP) by constracting the “modulus” signal by calculating the square root of the sum squares of X and Y components, without hodogram analysis.