Underground mapping of utility lines using impulse radar

The use of radar in an underground environment presents a number of practical difficulties. The paper describes a specific application to the mapping of buried utility lines, and other objects below city streets, prior to excavation for repair work or new construction. The system combines an impulse radar, using crossed polarised dipole antennas for transmitting and receiving, respectively, with a computer for data processing and map printing. The system is self contained and is mounted in a van, so that maps may be recorded wherever the ground is sufficiently level for operation of the wheeled antenna cart. Maps are presented as grey-scale plan views or vertical sections.