I.V. Chebotar1, M.T. Baldychev2, A.A. Omelshin3, V.A. Romakhin4

1–4 Military University of Radio Electronics (Cherepovets, Russia)

Currently, the development of aerospace technologies allows for an intensive build-up of the grouping of low-orbit spacecraft (LOS), as well as the development and commissioning of unmanned inter-medium aircraft (IMA) capable of flying in the Earth's atmosphere at an estimated range of over 10,000 km at speeds multiple times the speed of sound. The dual purpose of LOS and IMA (the possibility of use as a means of destruction) causes the need for their timely detection by means of monitoring the air (space) situation. The features of the trajectory and speed characteristics of the LOS and IMA impose significant restrictions on their timely detection by active radar means. The actual direction of solving the problem of monitoring the air (space) situation for the presence of LOS and IMA is the use of passive radar. The analysis of the features of the use of LOS and IMA showed that satellite data relay systems (SDRS) are widely used to provide communication with ground subscriber terminals (GST), transmission of control commands and telemetry of LOS and IMA, including those equipped with non-regenerative repeaters that transmit signals without making changes to their frequency-time structure. At the same time, it is known that the unique spatio-temporal characteristics of the movement of LOS and IMA, including high linear flight speed, affect the time-frequency parameters of the signals of the onboard radio-electronic means (REM) transmitted to the SDRS. Thus, a promising approach to solving the problem of tracking the use of LOS and IMA at the stage of detecting the fact of flight of these aircraft can be the analysis of the frequency-time parameters of SDRS signals by means of passive radar, providing for the determination of the speed characteristics of the movement of mobile objects. For passive radar equipment, a well-known approach to determining the speed characteristics of the movement of mobile objects in aerospace is the analysis of the difference in the Doppler frequency shifts of the onboard REM signal, the so-called passive difference-Doppler location. To ensure the possibility of estimating the linear velocity of mobile objects by means of passive radar at a considerable distance exceeding the range of direct radio visibility, as well as, as a consequence, for the early detection of the facts of the flight of the LOS and IMA, it is proposed to process the signals of the onboard REM of mobile objects, taking into account the known spatial characteristics of the orbital position of the repeater satellite (RS) on the geostationary orbit (GEO), limited the area of space in which the trajectories of the movement of mobile objects serviced by the SDRS are located, and the features of non-regenerative retransmission of radio signals by calculating the difference in Doppler frequency shifts of the signal received by the passive radar at various points in time. The proposed method provides for the analysis of several consecutive measurements of the carrier frequency of the signal of the onboard REM of a mobile object and calculations based on the measurement data of the rate of change of the carrier frequency (RCCF). The main factor affecting the magnitude of the RCCF signal of the onboard REM is the linear velocity of the mobile object. The integration of the proposed method into the hardware and software of passive radar technical means will allow us to consider the RCCF of the on-board REM signal relayed by the SDRS as a sign of recognition of the LOS and IMA when monitoring the air (space) situation. The results of computer modeling allow us to assert a relatively high separating ability of the selected feature – the RCCF of the retransmitted signal of the onboard REM, which provides recognition with the required probabilities of LOS and IMA in a variety of all mobile objects serviced by the SDRS, under typical conditions of receiving RS signals on the GEO by a passive radar technical means.

Chebotar I.V., Baldychev M.T., Omelshin A.A., Romakhin V.A. A method for estimating the linear velocity of a mobile object by a passive radar technical means outside the direct radio visibility zone. Electromagnetic waves and electronic systems. 2023. V. 28. № 3. P. 46−54. DOI: https://doi.org/10.18127/j15604128-202303-06 (in Russian)

1. Bykov I.M. Automated command and control system of troops and weapons as the basis of a comprehensive system for countering high-precision weapons. Information-measuring and Control Systems. 2021. V. 19. № 6. P. 29–36. DOI 10.18127/j20700814-202106-03. (in Russian)
2. Acton J.M. A silver bullet? The right questions about the "non-nuclear rapid global strike". Ed. by E. Myasnikov. М.: Moscow Carnegie Center. 2014. 228 p. (in Russian)
3. Novikov Ya.V. Lecture "Russian Aerospace Defense System: challenges and prospects". [Electronic resource] – Access mode: https://znanierussia.ru/library/video/lekciya-sistema-vozdushno-kosmicheskoj-oborony-rossii-vyzovy-i-p-47?ysclid=lfwb6iaqve652584423, date of reference 10.04.2023. (in Russian)
4. Sklyar B. Digital communication. Theoretical foundations and practical application. 2nd ed. Trans. from English by E.E. Groza and others. М.: Williams. 2016. 1099 p. (in Russian)
5. Dudakov N.S., Morozov P.A., Putyato S.A., Yakubovsky S.V. A model of an air situation data storage management system for solving highly dynamic tasks of automating the control of aviation and air defense forces. Information-measuring and Control Systems. 2022. V. 20. № 3. P. 4–8. (in Russian)
6. Chernyak V.C. Multi-position radar. M.: Radio and communications. 1993. 416 p. (in Russian)
7. Patent for the invention RUS2617830 dated 28.04.2017. A method of passive single-position angle-difference-Doppler location of a radio-emitting object moving in space and a radar system for implementing this method. Dzhioev A.L., Omelchuk I.S., Tyurin D.A., Fomichenko G.L., Fomichenko G.G., Yakovenko V.V. (in Russian)
8. Bakhvalov N.S., Zhidkov N.P., Kobelkov G.M. Numerical methods. M.: Binom. Laboratory of Knowledge. 2003. 636 p. (in Russian)
9. Idje V., Dreiard D., James F., Rus M., Sadule B. Statistical methods in experimental physics. Ed. by A.A. Tyapkin. Trans. from English by V.S. Kurbatov. М.: Atomizdat. 1976. 336 p. (in Russian)
10. Gorelik A.L. Barabash Y.L., Krivosheev O.V., Epstein S.S. Selection and recognition based on location information. M.: Radio and Communications. 1990. 240 p. (in Russian)