Impact of the Ionosphere Disturbed by Rocket Plume on OTHR Radio Wave Propagation

Abstract

AbstractThe main chemicals of rocket exhaust plume are released into the ionosphere, which cause three‐dimensional (3‐D) disturbances. By simulating the disturbance, we investigate the influence of ionospheric disturbance by the chemical release on the propagation of over‐the‐horizon radar (OTHR) waves. Based on the absorption simulation model, the absorption loss of OTHR waves caused by rocket plume was simulated. Using 3‐D digital ray tracing, we simulated the propagation path of radio waves in the “ionospheric hole” region. The simulation results show that the absorption loss of short waves decreases with an increase in the frequency and elevation angle of the ray. The absorption loss in the year of high solar activity is significantly higher than that in the year of low solar activity. The absorption value is largest at noon and smallest at night. In terms of seasonal variation, the absorption of radio waves is strongest in summer and weakest in winter. Additionally, the ionospheric hole area increases with the release time. The 6 MHz high‐frequency waves cannot reach the disturbance height and are completely reflected to the ground. Most of the 8 MHz radio waves are reflected to the ground, and some of them pass through the ionosphere. The radio waves at 10, 15, and 20 MHz can pass through the hole area of the ionosphere. Moreover, the ionospheric disturbance generated by the plume has a focusing effect on the propagation of OTHR shortwaves. With the increase in radio frequency, the focusing height gradually increases, and the focusing effect gradually weakens.