3DSymSam is short for 3D symmetric sampling. Symmetric sampling in 2D seismic data acquisition was introduced in “Seismic Wavefield Sampling” (Vermeer, 1990) and expanded to 3D in “3-D symmetric sampling” (Vermeer, 1994). Symmetric sampling is based on a corollary of the reciprocity theorem which asserts that the wavefields in common shot gathers and in common receiver gathers have the same physical properties.

3DSymSam – Geophysical Advice provides advice on 3D seismic survey design based on 3D symmetric sampling theory and offers courses on 3D seismic wavefield sampling and various acquisition techniques.

This website also contains some contributions to current and past geophysical discussions.

In October 2012 the SEG published “3D seismic survey design, second edition” by Gijs J.O. Vermeer. This edition is an extensive update of the first edition, which was published in 2002. A Chinese translation of the first edition appeared in 2008.

The figure below is Figure 5 in “Compensating missing source points” published in December 2021 issue of the CSEG Recorder, see also News.

Effect of compensation shots (red curved lines) and receivers (horizontal blue line segments) on coverage using reciprocal OVT gathers with offsets {(1500-2000),(1500, 2000)}; regular fold should be 2.