Hardware and Software Implementation of Magnetic Direction Finding Sensors

Lightning locating system (LLS) is useful for public to warn them as soon as the sensors detect the lightning strike. A common LLS uses various detection techniques such as time difference of arrival (TDOA), magnetic direction finding (MDF) and interferometry. Using MDF method, the direction of the horizontal component of the magnetic field generated by the lightning flash was obtained by magnetic crossed loops. Two vertical and orthogonal loops with planes oriented NS (north-south) and EW (east-west) were used, each to measure the magnetic field to obtain the direction of the source. Loop antennas are low frequency receiving sensors using in applications such as oil exploration, geophysical research, and survival communications. The loop antennas are sensitive to the magnetic field, but not the electric field. The incoming magnetic field induces voltage in the loop antenna. The induced voltage is proportional to the area of the loop (A), multiplied by the derivative of the magnetic field component perpendicular to the area of the loop. Cross loop antenna consists of two orthogonal magnetic loops. By measuring the induced voltage at each loop, the component of the magnetic field can be obtained. This research investigates the implementation a three-station MDF based system.