The enigma of arrays

The debate over arrays vs. single-point recording continues. In college (in the 1980s) we learnt that arrays can suppress certain forms of seismic noise and that the array itself acted as a multiplier to our stacking fold with regard to random noise. To understand the impact of arrays on our seismic data we need to challenge these fundamental truths about array behaviour and look more closely at what is taking place when we sum sensor responses from multiple receivers spread over an area. There is a great wealth of published material available on this topic with many experimental results from the field. However, the materials derived from these works never seem to result in an industry-wide conclusion which answers the question ‘is an array better or worse than a single point sensor?’. The default is often to continue on with arrays in acquisition since it has always been done that way in the past. With the introduction of very high channel count systems and very dense acquisition geometries it seems apparent that continued use of arrays must be under threat. This article hopes to challenge some of the fundamental assumptions about array behaviour.