{'fraction_non_alphanumeric': 0.013584117032392894, 'fraction_numerical': 0.006269592476489028, 'mean_word_length': 5.344370860927152, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Modelling of effect of propagation of lightning electromagnetic pulse over rough ground

The propagation effect of lightning-produced electromagnetic pulse over a large mountainous region in southern-west China has been investigated. The regional geometry data are adopted from a global digital elevation model named GTOPO30 with a horizontal resolution of 30 arc seconds and vertical accuracy of about 30 m. FDTD (Finite-difference time-domain method) is used to calculate the electromagnetic fields generated by lightning return strokes at various locations in the region. In comparison with a flat region, it is found that the topography of the region has large influences on the lightning - produced electromagnetic field waveforms and its propagation properties. Quantitative results of the simulation can be used to improve the performance of a lightning location network in mountainous region in terms of the lightning strength and location accuracy.