Effect of atmospheric refraction on VHF lightning location

In order to improve the precision of lightning location, the lightning location error caused by atmospheric refraction was researched in this paper. Using the data detected by GPS sonde calculate the atmospheric refractivity changing with height. On this basis, the effect of the atmospheric refraction to lightning location (magnetic direction finder (DF), time-of-arrival (TOA) and combination of the two) is analyzed, and the error model of atmospheric refraction is established respectively. According to station measured elevation, calculate the real elevation of lightning source and the refraction error caused by atmospheric refraction. The simulation results show that the most significant impact of the multi-station techniques is the DF, the maximum value of refraction error can reach to 116.52m, the mean value is 32.18m. To the TOA technique, the maximum value of refraction error is about 49.64m, the mean value is 14.21m. To the combination technique, the maximum value is 56.70m, the mean value is 19.49m. Furthermore, if taking far station´s direction to intersect, the refraction error is close to 1.6 times as selecting the near station. To ensure the positioning error caused by atmospheric refraction less than the error of GPS time synchronization, the distance between stations of the three methods should be no more than 28 km, 60 km, 45 km, which can lay a foundation for the construction of lightning detection network.