Synchronization of the radar signal repeater operation based on the quasi-matched filtering method

Аuthors

Titov K. I., Shulzhenko A. V.^*

Mlitary spaсe Aсademy named after A.F. Mozhaisky, Saint Petersburg, Russia

*e-mail: vka@mil.ru

Abstract

The article presents the principle of forming test noise-like areas on radar images. The areas have a limited size and are characterized by specified average brightness values. It is being developed for radiometric calibration of space-based synthetic-aperture radars. The principle of forming test noise-like areas is based on the partial (controlled) destruction of the coherence of relayed signals. Time synchronization of the repeater operation with the repetition period of the probing pulses is necessary for its implementation. High requirements for time synchronization accuracy amount to units of nanoseconds and cannot be met by a classical threshold amplitude detector.
The aim of the work is to ensure the required accuracy of synchronization of the active calibration means. To achieve the aim, a special device can be used, the basis of which is a filter of radar probe pulses. The main problem of the work is to develop such a filter.
To solve the problem, quasi-matched filtering of probing pulses is used. In a quasi-matched filter, in the absence of a priori information on the amplitude-frequency characteristic of probing signals, the preceding complex-conjugate pulse is used to convolve each subsequent pulse.
The result of the work is proposals for the design of a device for synchronizing the operation of active means of calibration of synthetic-aperture radar based on quasi-matched filtering, as well as an assessment of the efficiency of the application of the proposed method.
The developed method of quasi-matched filtering was tested in the course of analytical and simulation modeling. The results of modeling show that the required accuracy of time synchronization of the repeater can be ensured by using a synchronization device based on the proposed method when solving the problem of forming test noise-like areas on radar images for their radiometric calibration.
The proposed method of quasi-matched filtering of probing radar pulses can be used for:
- developing active means of calibrating synthetic-aperture radar and assessing the radiometric resolution of radar images;
- conducting a technical analysis of probing pulses of prototypes of space radar means for remote sensing of the Earth during flight tests.

Keywords:

synthetic aperture radar; radiometric calibration; relay; synchronization device; quasi-coherent filtering

References

1. Sakhno I.V., Il'in A.L., Titov K.I., Shul'zhenko A.V. Rezul'taty eksperimental'noi otsenki real'no dostizhimykh kharakteristik samoletnoi RSA (The results of the experimental evaluation of the realistically achievable characteristics of the aircraft radar). URL: https://www.mivlgu.ru/conf/armand2012/pdf/S4_16.pdf
2. Gusev S.N., Sakhno I.V., Khubbiev R.V. Methodology for assessing the quality of formation of virtual objects on radar images. Trudy MAI. 2019. No. 104. (In Russ.). URL: https://trudymai.ru/eng/published.php?ID=102169
3. Gusev S.N., Miklin D.V. A simulator model of test radar signals of aviation ground survey systems. Trudy MAI. 2020. No. 112. (In Russ.). URL: https://trudymai.ru/eng/published.php?ID=116355. DOI: 10.34759/trd-2020-112-11
4. Zanin K.A. Development of a model for estimating the spatial resolution of a synthetic aperture space radar. Trudy MAI. 2017. No. 96. (In Russ.). URL: https://trudymai.ru/eng/published.php?ID=859315
5. Il'in A.L., Shul'zhenko A.V., Shul'zhenko A.D. The principle of forming test local noise-like regions on radar images by re-emitting probing signals with partial destruction of their coherence and requirements for the accuracy of time synchronization of repeater operation when solving problems of radiometric calibration of radars with synthesized aperture. Vestnik NPO im. S.A. Lavochkina. 2022. No. 4. P. 60–67. (In Russ.).
6. Levin B.R. Teoreticheskie osnovy statisticheskoi radiotekhniki (Theoretical foundations of statistical radio engineering). Moscow: Radio i svyaz' Publ., 1989. 656 p.
7. Il'in A.L., Shul'zhenko A.V., Shul'zhenko A.D. Features of the use of aircraft carriers in testing space radar survey equipment. Trudy Voenno-kosmicheskoi akademii imeni A.F.Mozhaiskogo. 2019. No. 670. P. 159-163. (In Russ.).
8. Il'in A.L., Titov K.I., Shul'zhenko A.V. Using experimental data to assess the effect of incoherent averaging on the decoding properties of radar images. Trudy Voenno-kosmicheskoi akademii imeni A.F. Mozhaiskogo. 2014. No. 645. P. 113-116. (In Russ.).
9. Verba V.S., Neronskii L.B, Osipov B.G., Turuk V.E. Radiolokatsionnye sistemy zemleobzora kosmicheskogo bazirovaniya (Space borne radar systems for terrestrial observation). Moscow: Radiotekhnika Publ., 2010. 680 p.
10. Mukhtarov E.I., Petrov A.S. Analysis of distortions that occur when filtering signals with linear frequency modulation. Trudy MAI. 2024. no. 135. (In Russ.). URL: https://trudymai.ru/eng/published.php?ID=179690
11. Gusev S.N. The method of software formation of the trajectory signal in solving the problem of calibration of radar systems with synthesized antenna aperture. Izvestiya Tul'skogo gosudarstvennogo universiteta. Tekhnicheskie nauki. 2017. No. 6. P. 368-377. (In Russ.).
12. Gorbunova A.A. Development of an algorithm for obtaining a point portrait of a complex target based on a complex radar image. Trudy MAI. 2011. No. 45. (In Russ.). URL: https://trudymai.ru/eng/published.php?ID=25366&PAGEN_2=2
13. Shirman Ya.D. Radioelektronnye sistemy. Osnovy postroeniya i teoriya (Radioelectronic systems. Fundamentals of construction and theory: a reference book). Moscow: Radiotekhnika Publ., 2007. 510 p.
14. Kondratenkov G.S. Radiovidenie. Radiolokatsionnye sistemy distantsionnogo zondirovaniya Zemli (Radio vision. Radar Systems for Earth Remote Sensing). Moscow: Radiotekhnika Publ., 2005. 368 p.
15. Al'rubei M.A. Comparative analysis of interpolation methods for estimating the frequency of a sampled harmonic signal. Trudy MAI. 2023. No. 130. (In Russ.). URL: https://trudymai.ru/eng/published.php?ID=174612. DOI: 10.34759/trd-2023-130-15
16. Volosyuk V.K., Pavlikov V.V. Tsifrovye metody obrabotki informatsionnykh protsessov. V. 2 (Digital methods for informatio processes processing. V. 2). Khar’kov: Khar’kovskii aviatsionnyi institut Publ., 2012. 78 p.
17. Sychev M.I., Osipov P.V. Trajectory processing of radar information based on a multi-model approach. Trudy MAI. 2023. No. 129. (In Russ.). URL: https://trudymai.ru/eng/published.php?ID=173031. DOI: 10.34759/trd-2023-129-19
18. Korolenko P.V., Ryzhikova Yu.V. Modelirovanie i obrabotka sluchainykh signalov i struktur (Modeling and processing of random signals and structures). Moscow: MGU imeni M.V. Lomonosova Publ., 2012. 67 p.
19. Cook Ch. E., Bernfeld M. Radar signals, London: Academic Press Inc, 1967, 531 p.
20. Jirousek M, Döring B.J, Looser P., Schwerdt M. Linearity Measurements of an Accurate Transponder for Calibrating Future Spaceborne SAR Systems. Proc. of 9th European Conference on Synthetic Aperture Radar Conference EUSAR-2012, Nuremberg, Germany, 2012. P. 67 70.
21. Liu Chun-Yang, Jiao Yong-Chang. SAR Echo-wave Signal Simulation Systems Based on MATLAB. International Conference Microwave and Millimeter Wave Technology (ICMMT), Shenzhen, China, 2012. V. 5, P. 1-4. DOI: 10.1109/ICMMT.2012.6230417

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