Calibration of direction finder

Lightning electromagnetic pulse direction finders have to be calibrated in order to estimate lightning current peak values from a distant measuring method. In the current investigation, a lightning direction finder was calibrated by using 4 different methods in laboratory and in field. All four calibration results are in good agreement each others. The limited bandwidth (250 kHz) of the DF causes the elongation of the rise time by about 1.5 μs. Sensitivity of the DF against lightning EM field is 17.1 LLP units per V/m, equivalent to 0.19 V per V/m, (62% from sensitivity at 40 kHz).