CMP fold: A meaningless number?

3D Seismic Survey Design, Second edition

“…Another instructive illustration of the effect of denser sampling is discussed by Lansley (2004b), reproduced here as Figure 4.5. Lansley uses the same data set (acquired with relatively small shot and receiver sampling intervals of 110 ft [33.5 m]) to compare coarse sampling with dense sampling.…”

“…Equation 4.18 is derived under the assumption of equal signal and noise characteristics on the recorded 2D and 3D traces. If source strength were different, it should be taken into account Lansley (2004b). observes that Krey's formula (and this applies to equation 4.18) implies trace density should be maintained for equal S/N.…”

Directional interpolation of multicomponent data

“…Seismic spatial sampling refers to the distribution of shotpoints (source firing locations) and recording positions (receiver's locations for a given fired source). In a 3D experiment, ideally, that distribution should sample both sides (source and receiver) with high enough density over a 2D carpet covering the area under study (Vermeer 2002;Malcolm Lansley 2004). The goal is to measure seismic data that are properly sampled in all spatial dimensions: inline (x), crossline (y), offset, and azimuth.…”