Estimation of parameters of ionospheric wave disturbances on the basis of measurements of the Doppler shift of signal frequency of low-orbiting satellites

Abstract

[1] Calculations of the Doppler shift of the frequency (DSF) of a UHF signal under given models of a wave disturbance (WD), undisturbed medium, and particular orbits of low-orbiting (LO) satellites showed that there is an angle-of-approach effect. On the basis of the angle-of-approach effect a method of estimation of model parameters of medium-scale WD on the basis of measurements of DSF of signals from LO satellites in one observation point is developed. A trend in DSF variations is detected in the initial time series. Using this trend, the global model of the undisturbed ionosphere is corrected. For the parameters estimation, calculated trajectory parameters of the satellite and recordings of DSF variations are used. The numerical experiment carried out demonstrates the efficiency of the method developed. The method was tested at a series of DSF registrations received from LO satellites of the Tsykada type in 2002–2004. The analysis of DSF registrations showed that at high zenith angles for the orbits close to the central ones, WD disturbances with a vertical component are often observed. In such cases, the vertical wavelength can reach 140 km. For horizontal WD, the estimates of the wavelength give values >100 km. The range of variations of the maximum relative disturbance of the electron concentration is 1–7%.