Lightning VHF Polarization Imaging of Recoil Leaders

We proposed two kinds of location methods for an irregular VHF interferometer and found that a non-coplanar configuration can improve location precision. The theoretical distribution of the time uncertainty has been derived and the systematic time error can be calibrated for a non-coplanar array. Besides, we update our interferometer with a polarization detection function, and the polarization parameter can reveal more information about the breakdown process. A bolt-from-blue lightning was analyzed here, and there are several recoil leaders occurred at the later stage. The polarization parameter shows the breakdown direction of the recoil leader is nearly the same direction as the lightning channel.