Editing Wave (section)

==== Reflection of plane waves in a half-space  ====
{{further|Reflection coefficient}}
The propagation and reflection of plane waves—e.g. Pressure waves ([[P wave]]) or [[S-wave|Shear waves (SH or SV-waves)]] are phenomena that were first characterized within the field of classical [[seismology]], and are now considered fundamental concepts in modern [[seismic tomography]]. The analytical solution to this problem exists and is well known. The frequency domain solution can be obtained by first finding the [[Helmholtz decomposition]] of the displacement field, which is then substituted into the [[wave equation]]. From here, the [[Wave equation#Plane-wave eigenmodes|plane wave eigenmodes]] can be calculated.{{citation needed|date=May 2023}}{{clarify|Unintelligible to the ordinary reader|date=May 2023}}