Radiation from a downhole air gun source

Vertical seismic profiling (VSP) experiment at Salt Valley, Utah. Emphasis on primary radiations from the air gun source and secondary radiations from the bottom of the source hole. The observed primary radiation pattern agrees very well with theory developed for a volume displacement source acting on the axis of a fluid-filled hole. The observed secondary radiations, whose amplitudes were much stronger than the primary radiations, can be explained by calculating the wave field resulting from the application of an equivalent point force in an infinite medium, which was caused by the reflection of a tube wave at the bottom of the source hole.--Modified journal abstract.