A new-developed narrowband radio interferometer system and its preliminary observation result onlightning discharge

摘要

Based on the data obtained by the narrowband VHF radio interferometer system in inland plateau of Gansu province in China in the summer of 2006, a number of features of the lighting have been depicted. This interferometer system utilizes multiple baselines to determine the direction of lighting radiation sources in two dimensions (azimuth an elevation) as a function of time during close lighting discharges. It operated at a center frequency of 280 MHz with a bandwidth of 6 MHz with microsecond time resolution. The electric field and radiation measurements were also used to reflect the charge motion which provided the other dimension. Combining these systems we obtained pictures which well depicted the lightning’s location and development with time. Some events of lightning development were well located including the preliminary breakdown process, “K” type events, dart leaders and attempted leaders. The results confirm the previous conclusions that dart leaders, in-cloud “K” events, and attempted leaders are the same phenomena except that dart leaders have more energy enabling them to reach the ground.