Determining the orientation of a seismic receiver, a seismic receiver, and a method or seismic surveying

Abstract

The invention provides a method of determining the orientation of a seismic receiver () from seismic data acquired at the receiver (). The determined orientation can be taken into account in subsequent analysis of the seismic data. This avoids inaccuracies that can occur if the receiver orientation is estimated. In a preferred embodiment the horizontal spatial derivatives of the pressure measured at the receiver are used in the determination of the orientation of the receiver. These may be calculated on either the source side or the receiver side. These are combined with horizontal components of the particle displacement, velocity or acceleration (or a higher time-derivative of the particle displacement). Alternatively, horizontal spatial derivatives of the particle displacement measured at the receiver may be used in place of the horizontal spatial derivatives of the pressure. The invention also provides a seismic receiver () having three or more closely-spaced, non-collinear pressure sensors (). The provision of three or more pressure sensors enables the horizontal spatial derivatives of the pressure to be determined accurately.