common midpoint method

1. n. [Geophysics]
Method of seismic reflection surveying and processing that exploits the redundancy of multiple fold to enhance data quality by reducing noise. During acquisition, an energy source is supplied to a number of shotpoints simultaneously. Once data have been recorded, the energy source is moved farther down the line of acquisition, but enough overlap is left that some of the reflection points are re-recorded with a different source-to-receiver offset. Multiple shotpoints that share a source-receiver midpoint are stacked. The number of times that a common midpoint is recorded is the fold of the data.