Frequency independent directionally sensitive array in seismic surveying

Abstract

A novel array of vertically and horizontally spaced hydrophones is shown which is capable of high ratio of desired signal to noise because of good directional sensitivity when used with any seismic source. Alternatively, a novel directionally sensitive array of vertically and horizontally spaced seismic sources is disclosed for use in seismic surveying with any spread of hydrophones or geophones, again attaining a high ratio of desired signal to noise. A reception pattern (in the first case) and a radiation pattern (in the second place) is produced which essentially eliminates reception or radiation at all frequencies except for waves within a predetermined angle with respect to the array. The sensitivity is essentially constant within such angle for all frequencies and essentially zero outside it. This permits the array geometry to be adjusted so that there is high attenuation of undesired seismic waves, whether these be due to noise or other random waves, or are signal-generated waves from the seismic source but traveling in an undesired direction.