The sky waves generated by lightning are used to study the ionosphere. Previous studies calculated the reflection height of the ionosphere D region based on the time delay between the ground wave and the first skywave. This paper presents a new method for detecting the ionosphere. A set of ground wave delay values are used to calculate the height corresponding to the first and second skywaves. The height is determined by comparing the minimum difference between the corresponding heights of the first and the second skywaves. The height uncertainty is better than 1.5 km. Different from the previous studies for selecting lightning within a few hundred kilometers, the new method can select lightning within 2000 km for calculation. The results show that the errors caused by the ground wave delay can be corrected. For a region where lightning occurred in 24 h, the maximum height observed at night was 88 km, while the minimum height during the day was 66.7 km. In the absence of solar flare X-rays, the height during the day is strongly correlated with the solar zenith angle.

闪电产生的天波被用来研究电离层。以前的研究是根据地波和第一天波之间的时间延迟计算电离层D区的反射高度。本文提出了一种探测电离层的新方法。一组地波延迟值用于计算对应于第一和第二天波的高度。高度是通过比较第一和第二天波的对应高度之间的最小差异来确定的。高度不确定性优于 1.5 公里。与以往的研究选择几百公里以内的闪电不同，新方法可以选择2000公里以内的闪电进行计算。结果表明，地波延迟引起的误差是可以纠正的。对于24小时内发生闪电的地区，夜间观测到的最大高度为88公里，而白天观测到的最小高度为66.7公里。在没有太阳耀斑 X 射线的情况下，白天的高度与太阳天顶角密切相关。