The reflection seismic acquisition consists of generating seismic waves on surface and registering the amplitude variations for the waves train reflected from subsoil. These wave amplitude variations are caused for impedance (density x velocity) changes between different subsoil layers. The seismic wave travels between 2 medias with different impedances and part of its energy is reflected at the interphase while another part is refracted through the interphase. Reflection seismic consists in measuring the waves travel time from the seismic source to surface geophones, being reflected at the interphase. Knowing times and seismic waves speed allow to calculate the wave trajectory to obtain images of geometry and location of interphases (subsoil lithologies contacts).
Seismic waves can be generated using mechanical punchers and/or explosive (located source) or Vibroseis (controlled source). The amplitude variations are measured using several geophones (2D profiles or 3D mesh) and registered by a centralized acquisition system (seismograph) or by decentralized nodes.