Aerospace Technic and Technology

A method for processing spatio-temporal radio signals, which allows the formation of high spatial resolution images from aerospace carriers, has been synthesized. In this case, a swath is ±15° from the nadir relative to the flight line is considered. Traditionally this swath is not visible from aerospace carriers. A block diagram of an active-passive type radar is proposed. Initially the image obtained at the output of such a radar has a low quality of visual perception. Such image is called primary, since it was obtained at the stage of primary signal processing. The physical sense of such image is investigated. It approximately represents the operation of convolution of the ambiguity function with a spatial function proportional to the ideal image. The physical sense of the ideal image depends on the characteristics of the imaging system. In the problem under consideration, this is the specific radar cross section. In order to improve the quality of the image it is proposed additional processing (filtering). The paper substantiates the method of filtering (secondary processing) of images based on the solution of the inverse integral equation. It is shown that the exact solution to this equation is difficult to obtain because the form of the ambiguity function is not known exactly and can be estimated only approximately and, in addition, not for each ambiguity function it is possible to obtain a non-singular solution of the inversion equation. Therefore, an approximate solution to the problem is given. It solution is sufficient to solve practical problems of improving image quality. Using numerical simulation methods, the influence of the error in determining the shape of the uncertainty function on the task of improving image quality is studied. Examples of primary and secondary images obtained at the output of wideband active aperture synthesis systems with various geometries of spatially distributed antenna systems are given.

signal processing; image processing; high spatial resolution imaging; active aperture synthesis system; ultrawideband spatiotemporal signals

1HOPSat Formal Orbital Debris Assessment Report (ODAR) and End of Mission Plan (EOMP), Report Version: 8/28/18. 41 p.

Tadono, T., Mizukami, Y., Oka, A., Watarai, H., Sagisaka, M. Mission Overview of the Advanced Optical Satellite (Alos-3). IGARSS 2019 - 2019 IEEE International Geoscience and Remote Sensing Symposium, Yokohama, Japan, 2019, pp. 5883-5886. DOI: 10.1109/IGARSS.2019.8899187.

Wenjie, L., Shiqiang, Y., Chengliang, W. Yan, O. SBIRS: Missions, Challenages and Opportunities. 2019 IEEE 4th International Conference on Cloud Computing and Big Data Analysis (ICCCBDA), Chengdu, China, 2019, pp. 363-367. DOI: 10.1109/ICCCBDA.2019.8725616.

Motohka, T., Kankaku, Y., Suzuki, S. Advanced Land Observing Satellite-2 (ALOS-2) and its follow-on L-band SAR mission. 2017 IEEE Radar Conference (RadarConf), Seattle, WA, 2017, pp. 0953-0956. DOI: 10.1109/RADAR.2017.7944341.

Cumming, Ian G., Wong, Frank H. Digital Processing of Synthetic Aperture Radar Data: Algorithms and Implementation, Artech House Print on Demand, 2005. 660 p.

Kondratenkov, G. S., Frolov, A. Yu. Radiovideniye. Radiolokatsionnyye sistemy distantsionnogo zondirovaniya Zemli [Radiovision. Earth Remote Sensing Radar Systems]. Moscow, Radiotekhnika Publ., 2005. 368 p.

Volosyuk, V. K., Kravchenko, V. F. Statisticheskaya teoriya radiotekhnicheskikh sistem distantsionnogo zondirovaniya i radiolokatsii [Statistical theory of radio engineering systems for remote sensing and radar]. Moscow: Fizmatlit Publ., 2008. 704 p.

Kravchenko, V. F., Kutuza, B. G., Volosyuk, V. K., Pavlikov, V. V., Zhyla, S. S. Super-resolution SAR imaging: Optimal algorithm synthesis and simulation results. 2017 Progress In Electromagnetics Research Symposium - Spring (PIERS), 2017, pp. 419-425.

Wilson, Thomas L., Rohlfs, Kristen., Hüttemeister, Susanne. Tools of Radio Astronomy, Springer, Berlin, Heidelberg, 2009. 609 p. DOI: 10.1007/978-3-540-85122-6.

Thompson, A. R., Moran, J. M., Swenson Jr., G. W. Interferometry and Synthesis in Radio Astronomy, Third Edition, Springer International Publishing, 2017. 872 p. DOI: 10.1007/978-3-319-44431-4.

Pavlikov, V. V., Zhyla, S. S., Nguen Van Kiem, Odokienko, O. V. Optimal signal processing for radiometric imaging with multi-antenna & multi-band passive radars. Antenna theory and techniques. ICATT’2015 : proc. of the X Intern. conf., Apr. 21–24, 2015, Kharkiv, Ukraine, pp. 179-181.

Pavlikov, V. V., Volosyuk, V. K., Zhyla, S. S. Ultra-wideband Passive radars: Fundamental Theory and Applications. Proc. of Conference MMET-2018, July 2-5, 2018, Kyiv, Ukraine, pp. 56-61.

Pavlikov, V., Volosyuk, V., Zhyla, S., Van, H. N., Van, K. N. UWB active aperture synthesis radar the operating principle and development of the radar block diagram. 2017 IEEE Microwaves, Radar and Remote Sensing Symposium (MRRS), Kiev, 2017, pp. 27-30. DOI: 10.1109/MRRS.2017.8075018.

Pavlikov, V., Volosyuk, V., Zhyla, S., Van, H. N., Van, K. N. A new method of multi-frequency active aperture synthesis for imaging of SAR blind zone under aerospace vehicle. 2017 14th International Conference The Experience of Designing and Application of CAD Systems in Microelectronics (CADSM), Lviv, 2017, pp. 118-120. DOI: 10.1109/CADSM.2017.7916099.

Pavlikov, V., Volosyuk, V., Zhyla, S., Huu, N. V., Van, K. Nguen., Sobkolov, A. Signal Processing Algorithm for Active Aperture Synthesis Systems. 2019 IEEE 15th International Conference on the Experience of Designing and Application of CAD Systems (CADSM), Polyana, Ukraine, 2019, pp. 1-4. DOI: 10.1109/CADSM.2019.8779350.

Pavlikov, V. V., Volosyuk, V. K., Zhyla, S. S., Van, Huu N. Active Aperture Synthesis Radar for High Spatial Resolution Imaging. 2018 9th International Conference on Ultrawideband and Ultrashort Impulse Signals (UWBUSIS), Odessa, 2018, pp. 252-255. DOI: 10.1109/UWBUSIS.2018.8520021.

Gonzalez, R., Woods, R. Tsifrovaya obrabotka izobrazheniy [Digital image processing]. Moscow, Technosphere Publ., 2005. 1072 p.