It was conducted the research of the width of the working sector and the exactness of direct digital correlative-interferometric direction finder that uses reconstruction of spatial analytical signal. It is shown that the main operation that has a basic effect on the width of the working sector of the direction finder is the parallel two-dimensional filtration of the radiation with using of algorithm of fast Fourier transform (FFT). Two-dimensional filtration of the radiation should be carried out in frequency-spatial field of determination with using of two-step fast reconstruction of harmonic components of radio emission. At first stage the parallel frequency filtration of the radiation is implemented in direction finding channels on an intermediate frequency using fast Fourier transform algorithm, followed by rapid reconstruction of selected radiation in the time domain. At second stage the parallel spatial filtration is implemented using a digital synthesis of the multidirected directional pattern, which blocks the working sector of direction finding. It was determined that the width of working sector of direction finding is limited by parasitic distortions in the synthesis of the multidirected directional pattern and depends on the type of weight function of digital pattern formation (“window”), aperture size and number of elements of linear antenna lattice. It was conducted the research of the methods of rapid reconstruction of radio emission in their frequency filtration using real and complex forms of signal representation and its impact on the width of the working sector of direction finding. It was shown the expediency of using of complex reconstructed radiation implementations. The proposed method of expansion of the working sector of direction finding that uses reconstruction of spatial complex analytical signal provides the wider [15–165] degrees sector of direction finding and significantly simplifies direction finding algorithm.
1. Introduction into Theory of Direction Finding // Radiomonitoring and Radiolocation 2000/2001. — Rohde & Schwarz GmbH & Co. — KG Editor: Gerhard Kratschmer. — HW — UKD. 2. Rembovskiy А. М. Radiomonitiring — tasks, methods, devices / А. М. Rembovskiy, А. V. Ashyhmin, V. А. Kuzmin ; edited by А. М. Rembovskiy. — 2-nd ed. — М. : Hotline — Telecom, 2010. — 624 p. 3. Tsyporenko V. V. Direct digital method of correlation-interferometer direction-finding with reconstruction of spatial analytical signal / V. V. Tsyporenko // Visnyk of NTUU “KPI”. Ser. Radioengeneering. Radiodevices construction. — 2012. — № 48. — P. 75–84. 4. Dzvonovskaya А. L. Effectiveness of measuring of arrival angles of signal of the direction finder based on the maximum verisimilar method / А. L. Dzvonovskaya, А. N. Dmitrenko, А. V. Kuzmin // Radioengeneering and electronics. — 2001. — № 10. — P. 1242–1247. 5. Karavayev V. V. Statistic theory of passive location / V. V. Karavayev, V. V. Sazonov. — М. : Radio and communication, 1987. — 240. — (№ 27, Statistic theory of communication). 6. Bondarenko M. V. Direction-finding accuracy of the linear digital array under jitter conditions / M. V. Bondarenko // Microwave and Telecommunication Technology (CriMiCo), 2011 : 21th International Crimean Conference : Proceedings. 12–16 Sept., 2011. — P. 1128–1129. 7. Dan E. Dudgeon, Russell M. Mersereau. Multidimensional digital signal processing, Prentice-Hall, Inc., Englewood Cliffs, 1984.