Two-dimensional locations of VHF/UHF radiation sources emitted by lightning discharges are measured by both conventional narrowband and recently developed broadband interferometers during a field campaign in Darwin, Australia. Lightning channel images are recorded by an all sky video camera simultaneously. Observation results are compared with each other to confirm the function of the broadband interferometer. The conclusion of comparisons is that these observations show excellent agreement from the aspects of accuracy in azimuth and elevation. The potential capability of the broadband interferometer is evaluated. Advantages and disadvantages of both interferometers are discussed by introducing 2D mapping for additional flashes. It is shown that the broadband interferometer can locate multiple radiation sources, which propagate simultaneously through branching, in time and space. ¿ 2000 American Geophysical Union