An historical review of seismometer array development

The development of seismometer arrays in the context of nuclear detection is briefly outlined. The original array concept was for ten seismometers distributed in an area of a few square kilometers, but technological progress with magnetic tape recording and subsequent processing led to the construction of crossed linear arrays with dimensions of a few tens of kilometers. The linear arrays, with dimensions such that the delays between arrival at the various elements were of the order of the dominant signal period, demonstrated the usefulness of velocity filtering. Gradually there arose the concept of a few extremely large and powerful arrays replacing the network of many less sophisticated stations. Thus there has come into being the LASA, virtually an array of arrays.