РАЗРАБОТКА И ИСПЫТАНИЕ АППАРАТНО-ПРОГРАММНОГО КОМПЛЕКСА ДЛЯ НАЗЕМНОГО МОНИТОРИНГА ИОНОСФЕРЫ С ПРИМЕНЕНИЕМ SDR-ТЕХНОЛОГИИ, СЛОЖНЫХ ЗОНДИРУЮЩИХ ФАЗО-КОДО-МАНИПУЛИРОВАННЫХ СИГНАЛОВ И КВАДРАТУРНОЙ ОБРАБОТКИ
Authors: Иванов Д.В. , Иванов В.А. , Елсуков А.А. 
Published: February 2025

Представлены результаты разработки и испытания системы мониторинга ионосферы с использованием ФКМсигнала на универсальной SDRплатформе USRP. Рассмотрены этапы формирования и обработки ФКМсигнала для вертикального зондирования ионосферы с использованием полностью цифровой обработки за счёт использования принципа АЦП к антенне. Испытания устройства в ходе натурных экспериментов по вертикальному зондированию ионосферы в г. ЙошкарОле показали, что разработанные алгоритмы дают возможность измерять характеристики канала распространения сигналов КВдиапазона, используя при этом маломощные сигналы (менее 20 Вт).

Introduction. Ionosondes are the main tools for space weather research. This is important for space services and solving the problems of ensuring reliable ground communications using reflection of communication signals from the ionosphere. They continue to rely on HF systems of both longdistance strategic links and shorthaul tactical communications. The last one can ensure communicationы in regions with challenging relief (in the mountains). However, reliable HF communication requires to perform a control of the state of the ionosphere, which changes the conditions for propagation of communication signals. According to development level of the stateoftheart ionosondes, a current research trend in the area of tools engineering is the development of functionality of the ionosondes in terms of defined characteristics. Rapidly developing breakthrough softwaredefined radio (SDR) technology fosters ionosondes evolution due to the development of universal hardware platforms (for instance, USRP platform). This allows to significantly improve the methodological support of the tools and increase their flexibility. Research aim. Studies addressed to the problem of the development of hardware software system for ionospheric sounding by spread spectrum signals with phaseshift keying. System was designed with the use of SDR technology and flexible platform USRP N210. The novelty of the work is manifested in the unification of the components of the device (ionosonde), decreasing transmitted power and expanding the set of measured characteristics of the ionosphere and the ionospheric channel for propagation of HF signals. Findings. Algorithms for synthesis and processing of a complex digital signal using up and down frequency converters were developed. They are supported by the methods of optimal processing, coherent integration and narrowband interferences mitigation. The use of universal hardware components (USRP platform, power amplifier, receive and transmit antenna, personal computers), software modules and developed relevant models, methods and algorithms allowed to significantly decrease transmitted power and expand the set of measured characteristics of the ionosphere as a propagation medium for HF signals. Some technical characteristics of the ionosonde outperform the ones that provide competitors prototypes. Practical significance. Theoretical models, methods and algorithms were verified in the fullscale experiments on ionospheric sounding, carried out in YoshkarOla. The developed software was tested. The proposed approaches seem rather promising for stateoftheart shorthaul cognitive HF communication systems for regions with challenging relief.