Switching-Based FOA Geolocation Method with Frequency Offset by a Single Moving Observation Platform

This paper considers the problem of localization of a receiver using a sequence of Frequency Of Arrival (FOA) of the received signals, which are transmitted from the Low Earth Orbit (LEO) satellites. Especially, we focus on the problem of a biased frequency offset, which remains after the down-conversion of the received signals at the front end, to remove the carrier frequency components. This removal error causes a large localization error. In this case, the FOA localization with simultaneous frequency offset estimation (FOA-SFOE) should be applied. On the other hand, if FOA-SFOE is applied while there is no frequency offset, the localization accuracy degrades compared with the FOA localization with no frequency offset (FOA-WNFO). For this reason, we propose a localization method that switches the above localization algorithms depending on the value of the estimated frequency offset so that the appropriate method is selected regardless of the value of the frequency offset. To verify the effectiveness of the proposed method, the numerical simulation results are shown, and the results indicate a smaller localization RMSE of the proposed method compared with the above two localization methods.