The wireless trigger unit WTU1 is used to replace trigger cables if e.g. roads or rivers prevent a continuous seismic measurement. The wireless trigger unit WTU1 works with nearly all impulse sources including sledge hammers.
The wireless trigger unit WTU1 consists of two boxes which include the sender and the receiver unit. The sender will be connected to the source and the receiver to the seismograph. The sender and receiver units are placed in small and robust plastic cases which allow an easy operation.
The sledge hammer is used to generate seismic waves (P- or S-waves) at the surface. A piezotrigger element is attached to the hammer. The output piezo signal is transformed to a TTL pulse by a small box to provide an exact time break to the seismograph.
It is a suitable source for shallow downhole surveys up to a depth of 100 m.
The Landstreamer LS-24 is used to record P-, S- or surface waves. It consists of a number of horizontally or vertically oriented sensors mounted on sledges which are attached to a robust belt. The belt can be hooked to a vehicle and moved along the profile. A landstreamer is used to collect a large volume of seismic data in a short time. The landstreamer is suitable for MASW or reflection seismic applications especially on paved ground.