The data assimilation algorithm is a common algorithm in space weather research. In this paper, the time-frequency information in the dispersion spectrum of lightning whistlers received by the ZH-1 satellite is used as the observed value, and the international reference ionospheric model serves as the background model to construct the calculation model of the propagation time of lightning whistlers in the ionosphere. Kalman filtering is adopted to assimilate the electron density distribution along the propagation path of lightning whistlers. The results show that the situation where the electron density of the background model deviates greatly from the true value is significantly improved through data assimilation. The electron density after assimilation is in good agreement with the true value, which effectively helps realize the process of using observed values to correct the background value. On this basis, the influence of the frequency difference on the assimilation inversion effect is studied, and the results show that the assimilation effect is worse when the frequency difference between frequency points is less than 1 kHz.

Based on graphical processing unit acceleration, a new method of finite-difference time-domain scheme is proposed to simulate the interaction between electromagnetic waves and magnetized plasma in two-dimensional conditions. In this study, transversely electric and transversely magnetic are computed in time to avoid matrix operations involving Lorentz equations of motion. Compared to Young’s method, the new method reduces addition and multiplication by about 63% and 66%, respectively. The simulation results of ionospheric wave propagation show that the new method agrees well with Young’s method and the calculation speed is improved significantly.