The basic theory

measures of realization and the design of key components in detecting underground targets by nanosecond electromagnetic pulse method are described in this paper. A creative design of high quality traveling wave antenna is suggested by using sector antenna with three layers

high efficiency of radiation and good performance. The system can be used to detect underground metallic pipes and cavities about l meter deep. Fast and high resolution display system is used in the terminal to clearly display and print the target features. Compared to similar domestic and foreign products

this system is character-ized by high resolution and rapid signal processing

and can meet engineering requirements.