Seismic Receiver Type receiverType extReceiverType refinedReceiverType refinedExtReceiverType POSC 1.0 downhole geophone The geophone is used in a borehole, usually in conjunction with a VSP or check shot survey. land multi-component The receiver is designed to record three components of motion of the geophone. land geophone The geophone is designed for recording on the surface of a land environment. marsh geophone The geophone is designed for recording on the surface in a marsh environment. hydrophone The geophone is designed for recording in a marine or lake environment. unknown The type of recording instrument is not known.