Abstract:
The atmospheric noise includes the background noise from distant activities of lightning and the neighboring pulse noise of lightning. Based on a two-month observation data obtained by the WHU very-low-frequency (VLF) detection system at the Suizhou station (31.57°N, 113.32°E), the atmospheric noise is divided into the lightning impulse noise and the background noise. The noise intensities at three typical frequency bands (6, 16 and 27 kHz) are selected for a detailed analysis to obtain the basic information about the distribution characteristics of the atmospheric noise and the relative contributions of different types of noise to the total noise level. The accuracy of the CCIR atmospheric noise model in the mainland of China is also investigated by quantitative comparisons with the observations from the WHU VLF detector. A statistical evaluation of the atmospheric noise is conducted using a two-year (2016—2017) database of the WHU VLF detection system at Suizhou for 16 specific frequencies in range of 4-27 kHz to establish the statistical distribution profile of the atmospheric noise in this region.