A novel, moving-source, ground electromagnetic system has been developed. The system, named the "Genie", has been in routine field use since 1982. The system is based on measurement of the ratio of magnetic field amplitudes at two widely separated frequencies. The design is presented and compared with traditional horizontal loop electromagnetic (HLEM) systems. Field survey results show the system is effective in detecting conductors at shallow to intermediate depths in resistive environments. The system is shown to be roughly equivalent in many aspects to conventional HLEM systems with important advantages in areas of moderate to rough terrain.