Refraction and Faraday rotation in the Incoherent Scatter Radar technique

In this paper we consider the radiolocation equation for the Incoherent Scatter Radar (ISR) method, the equation accounts for refraction effect and Faraday rotation in the VHF frequency domain. Our research shows that we cannot ignore refraction in processing the incoherent scatter data when lag-product is used to obtain the ionospheric characteristics. Effect of refraction can explain some uncertainties that arise during processing and interpretation of the ISR data. This effect shows that together with the "ion line" of incoherent scatter spectrum, a relatively small "electron line" also plays a significant role in forming the ionosphere response. The “electron line” behaves as an additional "radar induced" wideband radiolocation signal affected by refraction and Faraday rotation; it depends on the ionosphere temperature and ion composition. The presence of a wideband “electron line” produces specific distortions of the ISR spectrum during 3D-forming of the ionosphere response inside the ISR antenna diagram pattern. During testing, we found that the signal from the ISR “electron line” can be measured at much higher altitudes comparing to the “ion line”. Hence, to improve the incoherent scatter technique, we can take the “electron line” and refraction into account.