Abstract In petroleum exploration, the geophysicist's task is to look beneath the earth's surface in the search for new deposits of oil and natural gas. Subsurface geologic structures of interest can be several miles deep. Geophysicists use the seismic reflection method in their search for oil and natural gas. The exploration geophysicist illuminates the earth's subsurface by means of an energy source that generates seismic waves. The subsurface rock layers transmit and reflect those seismic waves. A seismic survey consists of collecting seismic reflection data over a selected geographic area, called the prospect . The seismic reflection method, when considered as an instrument for remote detection, has much in common with other disciplines that are based on noninvasive techniques for finding the structure of an inaccessible body, such as medical imaging and nondestructive testing. What is seismic acquisition? The essential features of seismic data acquisition are as follows: (1) At a fixed point on the surface of the earth, a source of energy — such as an array of dynamite charges or air guns or swept-frequency vibrators (as in vibroseis) — is activated. Such an activated source is called a shot. (2) Seismic waves from the shot propagate downward from the source point and go deep into the earth ( Bois, 1968 ). (3) Eventually, the waves are reflected from geologic interfaces and propagate upward from those interfaces. A primary reflection is a reflection that travels directly down to the interface and then directly back up to the surface. A multiple reflection